Anterior-to-posterior uncinate joint stabilizer systems

ABSTRACT

A system for stabilizing a cervical spine segment includes a pair of uncinate joint stabilizers for stabilizing a respective pair of uncinate joints. Each uncinate joint stabilizer is elongated along a lengthwise dimension and is configured for placement in the respective uncinate joint with the lengthwise dimension substantially oriented along an anterior-to-posterior direction of the cervical spine segment. Each uncinate joint stabilizer has height configured to define spacing of the respective uncinate joint. Each uncinate joint stabilizer includes a generally cylindrical portion with cylinder axis in the lengthwise dimension. The generally cylindrical portion has threads for threading the uncinate joint stabilizer into the respective uncinate joint along the anterior-to-posterior direction. The threads are interrupted by one or more fenestrations configured to accommodate bone graft material, bone growth, and/or tissue displaced from the respective uncinate joint by the uncinate joint stabilizer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/553,556, filed on Aug. 24, 2017, which is a 35 U.S.C. §371filing of International Application No. PCT/US2016/019896, filed Feb.26, 2016, which claims the benefit of priority from U.S. ProvisionalPatent Application Ser. No. 62/121,260 filed on Feb. 26, 2015. All ofthe aforementioned applications are incorporated herein by reference intheir entireties.

BACKGROUND

The cervical spine is the neck portion of the spine. The cervical spinehas a series of seven vertebrae connecting the skull to the thoracicspine (upper back). These seven vertebrae are referred to as C1-C7, withC1 being closest to the skull and C7 being furthest from the skull. Eachpair of neighboring vertebrae forms a cervical spine segment that allowsmovement of the spine, such as rotation and flexion. Each cervical spinesegment includes an intervertebral disc that separates the two vertebrato allow for smooth joint movement and provide cushioning.

The cervical spine houses the spinal cord responsible for neuralcommunication between the brain and the body. Therefore, damage to thecervical spine can lead to neck pain, apparent pain in other parts ofthe body, and/or impaired functioning. For example, damage to thecervical spine may result in apparent arm pain or partial/complete lossof hand function. Although cervical spine damage may be caused bytrauma, cervical spine damage usually is a gradual process occurringwith aging. Common cervical spine damage includes degeneration of theintervertebral disc and degeneration of the uncinate joints locatedadjacent the intervertebral disc space. Intervertebral disc degenerationmay cause spinal cord or nerve impingement from the formation of bonespurs and/or intervertebral disc protrusion. Uncinate joint degenerationmay cause spinal cord or nerve impingement from the formation of bonespurs. Surgery may be required to resolve either of these issues.

Surgical methods used to resolve cervical spine damage traditionallyinclude cervical discectomy (removal of intervertebral disc). Thepurpose of such surgery is to restore proper spacing between thecervical vertebrae of the damage cervical spine segment. Theintervertebral disc may be replaced by a cage that includes bone graftmaterial for subsequent fusion of the cervical spine segment. A fusedcervical spine segment is stiff and does not allow for joint movement.Alternatively, the intervertebral disc is replaced by an artificial discdevice that allows for active joint movement of the cervical spinesegment.

Conventionally, cervical discectomy is performed from the front (theanterior side). To access the cervical spine segment, the surgeon (a)makes a skin incision in the front of the neck, (b) makes a tunnel tothe spine by moving aside muscles and retracting the trachea, esophagus,and arteries, and (c) lifts and holds aside the longus colli musclesthat support the front of the spine. Next, the surgeon screws pins intoboth the superior (upper) cervical vertebra and the inferior (lower)cervical vertebra of the cervical spine segment and uses these pins toincrease the intervertebral spacing. The surgeon then performs thecervical discectomy and inserts a cage into the intervertebral discspace.

When the cage includes bone graft material, bone growth within theintervertebral disc space takes place over the next several months,ultimately fusing the cervical spine segment. Each vertebral body (theportion of the vertebra located above or below the intervertebral discspace) has a denser shell of cortical bone surrounding an inner,cylindrical core of spongy cancellous bone. At the intervertebral discspace, the cortical bone shell forms a ring around the cancellous bone.Fusion of the cervical spine segment requires bone growth between thetwo cortical bone shells of the cervical spine segment.

SUMMARY

In an embodiment, a method for stabilizing a cervical spine segment,includes implanting a respective uncinate joint stabilizer into eachuncinate joint of the cervical spine segment to stabilize the uncinatejoints and thereby stabilize the cervical spine segment.

In an embodiment, a system for stabilizing a cervical spine segment,includes a pair of uncinate joint stabilizers for stabilizing arespective pair of uncinate joints of the cervical spine segment. Eachuncinate joint stabilizer is elongated along a lengthwise dimension andconfigured for placement in the respective uncinate joint with thelengthwise dimension substantially oriented along ananterior-to-posterior direction of the cervical spine segment. Eachuncinate joint stabilizer has height in a heightwise dimensionorthogonal to the lengthwise dimension. The height is configured todefine spacing of the respective uncinate joint.

In an embodiment, a system for distracting uncinate joints of a cervicalspine segment includes two tapered elements and an actuator. Theactuator is configured to couple with the tapered elements and changedistance between the tapered elements, to insert the tapered elementsinto the uncinate joints, respectively, from intervertebral disc spaceof the cervical spine segment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates implants that stabilize the uncinate joints of acervical spine segment, according to an embodiment.

FIG. 2 shows an axial view (along the spine) of a cervical vertebra thatis one of vertebra C3-C7.

FIG. 3 illustrates a method for stabilizing a cervical spine segment byinserting implants into the uncinate joints of the cervical spinesegment, according to an embodiment.

FIG. 4 illustrates a method for stabilizing the uncinate joints of acervical spine segment, using access to the uncinate joints viaanterior-to-posterior directions, according to an embodiment.

FIGS. 5A and 5B illustrate a threaded implant for stabilizing anuncinate joint, according to an embodiment.

FIGS. 6A and 6B depict a diagram showing, in an anterior view, a pair ofthe threaded implant of FIGS. 5A and 5B installed in the uncinate jointsof a cervical spine segment according to the method of FIG. 4, accordingto an embodiment.

FIGS. 7A and 7B illustrate a fenestrated, threaded implant forstabilizing an uncinate joint, according to an embodiment.

FIGS. 8A and 8B illustrate another fenestrated, threaded implant forstabilizing an uncinate joint, according to an embodiment.

FIG. 8C illustrates a cap for sealing a through-hole of the fenestrated,threaded implant of FIGS. 8A and 8B, according to an embodiment.

FIG. 8D illustrates a cap which is an implementation of the cap of FIG.8C, which further implements a locking lever, according to anembodiment.

FIGS. 8E and 8F show, in an anterior view, the fenestrated, threadedimplant of FIGS. 8A and 8B with the cap of FIG. 8D installed in uncinatejoint 120, according to an embodiment.

FIGS. 9A and 9B illustrate a shim implant for stabilizing an uncinatejoint, according to an embodiment.

FIGS. 10A and 10B illustrate, in an anterior view, the shim implant ofFIGS. 9A and 9B secured to an uncinate joint using additional hardware,according to an embodiment.

FIGS. 11A, 11B, 11C, 11D and 11E illustrate a locking implant forstabilizing uncinate joint 120, according to an embodiment.

FIGS. 12A and 12B show, in a posterior view, the locking implant ofFIGS. 11A-E) installed in an uncinate joint, according to an embodiment.

FIGS. 13A, 13B, 13C, and 13D illustrate a motion-preserving implant forstabilizing an uncinate joint, according to an embodiment.

FIGS. 14A and 14B show, in an anterior view, a pair of themotion-preserving implant of FIGS. 13A-D installed in the uncinatejoints of a cervical spine segment according to the method of FIG. 4,according to an embodiment.

FIG. 15 shows, in an anterior view, the motion-preserving implant ofFIGS. 13A-D secured to an uncinate joint using additional hardware,according to an embodiment.

FIGS. 16A, 16B, 16C, and 16D illustrate a bracket for securing twoimplants, located in the uncinate joints of a cervical spine segment, toone vertebra of the cervical spine segment, according to an embodiment.

FIGS. 17A, 17B, 17C, and 17D illustrate a screw-in implant forstabilizing an uncinate joint, according to an embodiment.

FIGS. 18A, 18B, 18C, and 18D illustrate an implant system including animplant, for stabilizing an uncinate joint, and a screw for insertingthe implant into the uncinate joint, according to an embodiment.

FIGS. 19A and 19B illustrate, in a posterior view, insertion of theimplant of FIGS. 18A-D), using the implant system of FIGS. 18A-D, intoan uncinate joint along an anterior-to-posterior direction, according toan embodiment.

FIG. 20 illustrates a method for stabilizing the uncinate joints of acervical spine segment, using access to the uncinate joints viamedial-to-lateral directions, according to an embodiment.

FIG. 21 illustrates a method for stabilizing the uncinate joints of acervical spine segment at least while performing cervical discectomy,according to an embodiment.

FIG. 22 illustrates a method of stabilizing the uncinate joints of acervical spine segment after intervertebral discectomy of the cervicalspine segment, according to an embodiment.

FIGS. 23A, 23B, 23C, and 23D illustrate a tapered implant forstabilizing an uncinate joint, according to an embodiment.

FIG. 24 illustrates another tapered implant for stabilizing an uncinatejoint, according to an embodiment.

FIG. 25 illustrates yet another tapered implant for stabilizing anuncinate joint, according to an embodiment.

FIG. 26 illustrates, in an anterior view, a pair of tapered implantslocated in the uncinate joints of a cervical spine segment, afterinsertion into the uncinate joints according to the method of FIG. 20,the method of FIG. 21, or the method of FIG. 22, according to anembodiment.

FIG. 27 illustrates, in an axial view, an actuator 2700 for insertingtapered implants into the uncinate joints of a cervical spine segment,according to an embodiment.

FIG. 28 illustrates, in an axial view, extensions that may be coupledwith tapered implants to extend the tapered implants in an anteriordirection, according to an embodiment.

FIG. 29 illustrates a tapered implant for stabilizing an uncinate joint,according to an embodiment.

FIG. 30 illustrates an intervertebral-disc-space implant configured forplacement in the intervertebral disc space of a cervical spine segmentto at least participate in securing a pair of tapered implants in theuncinate joints of the cervical spine segment, according to anembodiment.

FIG. 31 illustrates use of the intervertebral-disc-space implant of FIG.30 in the method of FIG. 20 or in the method of FIG. 22, according to anembodiment.

FIG. 32 illustrates an implant-loading system for stabilizing theuncinate joints of a cervical spine segment from the intervertebral discspace, according to an embodiment.

FIG. 33 shows the implant-loading system of FIG. 32 as implemented inthe method of FIG. 22, according to an embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 illustrates two exemplary implants 100 that stabilize theuncinate joints 120 a cervical spine segment 180 of a patient 170,according to an embodiment. Implant 100 may also be referred to as anuncinate joint stabilizer. Cervical spine segment 180 includes superiorvertebra 184 and inferior vertebra 186, wherein superior vertebra 184 isone of C3, C4, C5, and C6. Uncinate joints 120, also known as theuncovertebral joints or the joints of Luschka, are located adjacent theintervertebral disc space 140 of cervical spine segment 180. Uncinatejoints 120 are associated with cortical bone of cervical vertebrae 184and 186.

In one embodiment, implant 100 is a permanent implant that stays inplace over the life of the patient, unless surgically removed. Inanother embodiment, implant 100 is biodegradable and eventuallydegrades. In one embodiment, implants 100 lock the mobility of cervicalspine segment 180 and, optionally, include bone graft material thatpromotes fusion of uncinate joints 120. In one fusion-promoting example,implant 100 is porous or have cavities configured to accommodate bonegraft material. In another fusion-promoting example, at least a portionof implant 100 is a porous portion composed of bone graft material thatpromotes bone growth in the pores thereof. Herein, “bone graft material”refers to a material that promotes bone growth. Exemplary bone graftmaterials include biological materials, stem cell based materials,synthetic bone growth promoting materials, other bone growth promotingmaterials known in the art, and a combination thereof. In anotherembodiment, implants 100 are motion-preserving implants that preserve atleast some degree of mobility of cervical spine segment 180.

Implant 100 is notably smaller than conventional implants placed inintervertebral disc space 140. Hence, implant 100 may be less expensive,require less hardware, and be installed in uncinate joints 120 usingless invasive methods than those associated with the installation ofconventional implants placed in intervertebral disc space 140.

Disclosed herein are methods that insert implants 100 into uncinatejoints 120 to stabilize cervical spine segment 180, while leaving intactintervertebral disc 150 located in intervertebral disc space 140.Herein, an “intact” intervertebral disc may refer to a disc that isentirely undisturbed by implants 100, or an intervertebral disc that isslightly altered by implant(s) 100 in a generally lateral dimension. Incertain embodiments, the methods disclosed herein stabilize cervicalspine segment 180 while preserving motion of cervical spine segment 180and also allowing for normal health and functionality of intervertebraldisc 150. These methods are, in certain embodiments, performed in aminimally invasive manner utilizing percutaneous access to uncinatejoints 120. In contrast, conventional stabilization of cervical spinesegment 180, based upon stabilization within intervertebral disc space140, requires anterior access to intervertebral disc space 140, andrelies on open access to intervertebral disc space 140. In one usescenario, the methods disclosed herein utilize biodegradable embodimentsof implants 100, which stabilize uncinate joints 120 for a durationsufficient for healing of an injury to intervertebral disc 150, butsubsequently degrades to play no or little role in the functionality ofcervical spine segment 180. Also disclosed herein are methods that useimplants 100 to stabilize uncinate joints 120 in conjunction withperforming cervical discectomy. Whether implants 100 are used inconjunction with cervical discectomy or coexist in cervical spinesegment 180 with an intact intervertebral disc 150, implants 100 mayinclude or be substantially composed of bone graft material to promote(a) fusion of uncinate joints 120 or (b) bony ingrowth in uncinatejoints 120 at the interfaces between implants 100 and one of cervicalvertebrae 184 and 186. Since the surfaces of uncinate joints 120 arecortical bone, such fusion is expected to be fast and strong.

FIG. 2 shows an axial view (along the spine) of a cervical vertebra 200that is one of vertebrae C3-C7. Cervical vertebra 200 is, for example,one or cervical vertebrae 184 and 186. Label 202 indicates the anterior(front) side of cervical vertebra 200 and label 204 indicates theposterior (back) side of cervical vertebra 200. Uncinate joints 120 arelocated adjacent intervertebral disc space 140. Cervical vertebra 200includes surfaces for forming facet joints 250 with a neighboringcervical vertebra 200. FIG. 2 further indicates the locations ofvertebral arteries 230 passing through cervical vertebra 200. The spinalcanal 260 is located posterior to intervertebral disc space 240. Thespinal cord passes through spinal canal 260. Nerve roots pass throughthe neural foramen along paths 270.

Referring now to FIGS. 1 and 2 in combination, each implant 100 may beinserted into the respective uncinate joint 120 along ananterior-to-posterior direction 210. Herein, “anterior-to-posteriordirection” refers to a direction that is generally from anterior side202 towards posterior side 204, such that access to uncinate joint 120along anterior-to-posterior direction 210 does not require passingthrough intervertebral disc space 140. Thus, when inserting implants 100into uncinate joints 120 along anterior-to-posterior direction 210,intervertebral disc 150 may be left intact. Alternatively, each implant100 may be inserted into the respective uncinate joint 120 along amedial-to-lateral direction 220. Herein, “medial-to-lateral direction”refers to a direction that is from intervertebral disc space 140 towardseither one of uncinate joints 120. Thus, when inserting implants 100into uncinate joints 120 along medial-to-lateral direction 220, implants100 are inserted into uncinate joints 120 from intervertebral disc space140.

FIG. 3 illustrates one exemplary method 300 for stabilizing cervicalspine segment 180 (FIG. 1) by inserting implants 100 into uncinatejoints 120 of cervical spine segment 180. In method 300, uncinate joints120 may be accessed via anterior-to-posterior directions 210 (FIG. 2) orvia medial-to-lateral directions 220.

In a step 310, method 300 stabilizes uncinate joints 120. Step 310includes steps 312 and 314. Step 312 distracts each uncinate joint 120to prepare uncinate joints 120 for insertion of implants 100. In oneexample of step 312, a surgeon inserts a distraction tool into eachuncinate joint 120 along anterior-to-posterior direction 210 or alongmedial-to-lateral directions 220, and uses this distraction tool to openuncinate joint 120. Herein, a “surgeon” may be assisted or replaced byrobotic equipment without departing from the scope hereof. Step 314places implants 100 into respective uncinate joints 120. Herein, a stepof placing an implant may also be referred to as a step of implanting anuncinate joint stabilizer. In one example of step 314, a surgeon insertsimplant 100 into each uncinate joint 120. Implants 100 used in step 314may also perform step 312, and step 314 may be performed concurrentlywith or prior to step 312, without departing from the scope hereof.

In one implementation of method 300, implants 100 are self-securing andstep 314 includes a step 315 of securing such self-securing embodimentsof implants 100 in uncinate joints 120. Herein, a “self-securing”implant is an implant that stays in place without use of additionalhardware. In one example, a self-securing embodiment of implant 100 hasfeatures that grip the surface of one or both of cervical vertebrae 184and 186 at uncinate joint 120. A “self-securing” implant may secureitself at least in part by cooperation with a tension band. Herein, a“tension band” refers to one or more ligaments of cervical spine segment180, which pull cervical vertebrae 184 and 186 toward each other. Hence,in one example of step 315, a surgeon places self-securing implants 100in respective uncinate joints 120, where each implant 100 cooperateswith respective uncinate joint 120 and, optionally, a tension band tosecure itself.

In one implementation, step 314 includes a step 316 of loading bonegraft material with, or into, implants 100 to promote subsequent (a)fusion of uncinate joints 120 or (b) bony ingrowth in uncinate joints120 at interfaces between implants 100 and one of cervical vertebrae 184and 186. In one example of step 314 implemented with step 316, a surgeoninserts, into each uncinate joint 120, an embodiment of implant 100carrying bone graft material. In another example of step 314 implementedwith step 316, a surgeon inserts, into each uncinate joint 120, anembodiment of implant 100 that has at least one void. This embodiment ofimplant 100 may include a porous portion, one or more fenestrations,and/or one or more cavities. Next, in this example, the surgeon loadsbone graft material into the at least one void of implant 100.

In implementations of method 300 that do not utilize self-securingembodiments of implants 100, step 310 may further include a step 317 ofsecuring implants 100 in uncinate joints 120. In one example of step317, a surgeon secures each implant 100 to one or both of cervicalvertebrae 184 and 186 using additional hardware, such as plates, screws,and/or pins.

In certain embodiments, step 310 includes a step 318 of monitoringlocations of implants 100 and, optionally, equipment used to performone, two, or all of steps 312, 314, and 317, to ensure that uncinatejoints 120 are stabilized without unintentionally harming otherstructures. Step 318 may monitor the locations of implants 100, andoptionally equipment used to handle implants 100, within patient 170relative to the location of important structures such as vertebralarteries 230 (FIG. 2), nerve roots passing through the neural foramen(along paths 270 of FIG. 2), and spinal canal 260. In one example ofstep 318, real-time imaging of at least a portion of cervical spinesegment 180 is performed concurrently with some or all of steps 312,314, and 317. This real-time imaging may include fluoroscopy and/orother imaging method(s) known in the art.

Although not shown in FIG. 3, step 310 may be preceded by a step oflocating uncinate joints 120, without departing from the scope hereof.

In one embodiment, method 300 further includes a step 320 of performingcervical discectomy. In one example of step 320, a surgeon removes atleast the majority of intervertebral disc 150 from intervertebral discspace 140. Step 320 may utilize methods known in the art. Optionally,step 320 is followed by a step 330 that installs anintervertebral-disc-space (IVDS) implant in intervertebral disc space140. In one implementation, step 330 includes a step 332 of loading bonegraft material into intervertebral disc space 140, together with or intothis IVDS implant, to promote subsequent fusion between cervicalvertebrae 184 and 186 within intervertebral disc space 140. In oneexample of step 332, an IVDS implant, with at least one void capable ofaccommodating bone graft material, is inserted into intervertebral discspace 140. Bone graft material may be loaded into the void(s) prior toor after insertion of the IVDS implant into intervertebral disc space140. In another example of step 332, the IVDS implant is a bag ormalleable container with bone graft material.

In implementations of method 300 that include step 320 but do notutilize self-securing embodiments of implants 100 and also do notimplement step 317, method 300 may further include a step 340,subsequent to step 320, of securing implants 100 in respective uncinatejoints 120. Step 340 is, for example, performed in a manner similar tothat of step 317.

Although for clarity not shown in FIG. 3, step 310 may utilize trialimplants to stabilize uncinate joints 120, without departing from thescope hereof. Each such trial implant is an embodiment of implant 100,which is removed at a later stage. In one example, the trial implantsare removed after step 320. When step 310 utilizes such trial implants,method 300 may include a later step of placing final implants 100 inuncinate joints 120. For example, method 300 may implement step 314 withfinal implants 100 after step 320 or during step 330.

FIG. 4 illustrates one exemplary method 400 for stabilizing uncinatejoints 120 (FIG. 1) of cervical spine segment 180, using access touncinate joints 120 via anterior-to-posterior directions 210 (FIG. 2).Method 400 is an embodiment of step 310 of method 300 (FIG. 3) and maybe performed percutaneously. Method 400 may be performed while leavingintervertebral disc 150 intact. In one implementation, method 400facilitates fusion of uncinate joints 120. In another implementation,method 400 preserves motion of cervical spine segment 180. In yetanother implementation, method 400 utilizes biodegradable implants that,after healing of an intervertebral disc injury, degrade and cease toplay a role in the function of cervical spine segment 180.

In a step 410, an access path to each uncinate joint 120 is formed alonga corresponding anterior-to-posterior direction 210, such that theaccess path is substantially in line with uncinate joint 120. In oneexample of step 410, for each uncinate joint 120, a guide wire isinserted into patient 170 along anterior-to-posterior direction 210.Herein, a “guide wire” refers to a wire that defines a direction andaids movement of tools and/or implants along this direction. A guidewire may refer to a Kirschner wire. The guide wire may be inserted to adepth of about 8-12 millimeters into uncinate joint 120. The guide wiremay be threaded to cooperate with implants having a threadedcannulation. In another example of step 410, for each uncinate joint120, a cannula is inserted into patient 170 along anterior-to-posteriordirection 210. In yet another example, an access path is drilled alonganterior-to-posterior direction 210, for example by implant 100 or adedicated drill. Step 410 may utilize methods known in the art. Forexample, for each uncinate joint 120, a surgeon may use a robot or otherdevice, mounted to patient 170 or mounted to a frame attached to patient170, to align a guide wire with anterior-to-posterior direction 210, andthen tapping the guide wire into patient 170 to reach uncinate joint120. In one example, the access path goes through a longus colli muscleof patient 170.

In an optional step 420, each uncinate joint 120 is distracted using adistraction tool inserted into uncinate joint 120 along thecorresponding access path formed in step 410. In one example of step420, for each uncinate joint 120, a surgeon moves a cannulateddistraction tool over a guide wire, placed in step 410, to reachuncinate joint 120, and then controls the distraction tool over theguide wire to distract uncinate joint 120. In another example of step420, for each uncinate joint 120, a surgeon directs the distraction toolto uncinate joint 120 through a cannula, placed in step 410, to reachuncinate joint 120, and then controls the distraction tool through thecannula to distract uncinate joint 120.

In a step 430, for each uncinate joint 120, implant 100 is inserted intouncinate joint 120 using the access path formed in step 410. In oneexample of step 430, implants 100 are cannulated and, for each uncinatejoint 120, a surgeon moves implant 100 over a guide wire to uncinatejoint 120. In another example of step 430, for each uncinate joint 120,a surgeon moves implant 100 through a cannula to uncinate joint 120.

In certain implementations of method 400, compatible with bothguide-wire insertion and through-cannula insertion of implants 100 intouncinate joints 120, each implant 100 includes threads and step 430includes a step 432 of using the threads to screw implants 100 intoplace in uncinate joints 120. Such threaded embodiments of implants 100are discussed below in reference to FIGS. 5A-8B, 13A-15, and 17A-18C. Inone such implementation, step 432 includes a step 433 of screwing aself-securing and threaded embodiment of implant 100 into each uncinatejoint 120, with the threads contacting both the superior surface andinferior surfaces of uncinate joint 120. The superior surface ofuncinate joint 120 is that of superior cervical vertebra 184, and theinferior surface of uncinate joint 120 is that of inferior cervicalvertebra 186. Exemplary implants compatible with step 433 are discussedbelow in reference to FIGS. 5A-8C. In another such implementation, step432 includes a step 434 of screwing a motion-preserving embodiment ofimplant 100 into each uncinate joint 120, with the threads contactingonly one of the superior surface and inferior surfaces of uncinate joint120, while the other one of the superior surface and inferior surfacesof uncinate joint 120 is allowed to move relative to implant 100, atleast during insertion of the implant into uncinate joint 120. Exemplaryimplants compatible with step 434 are discussed below in reference toFIGS. 13A-15 and 17A-D.

In another implementation of method 400, also compatible with bothguide-wire insertion and through-cannula insertion of implants 100 intouncinate joints 120, step 430 includes a step 436 of sliding implants100 into uncinate joints 120. Exemplary implants compatible with step436 are discussed below in reference to FIGS. 9A-12B. Optionally, step436 is followed by a step 437, wherein, for each uncinate joint 120, alock mechanism of each implant 100 is engaged to lock the position ofimplant 100 within uncinate joint 120. The lock may be engaged byrotating a portion of implant 100 to grip the surfaces of uncinate joint120. Exemplary implants with such a lock mechanism are discussed belowin reference to FIGS. 11A-12B.

Optionally, step 430 includes a step 438 of loading bone graft materialinto each uncinate joint 120 together with, or into, the correspondingimplant 100, to promote (a) fusion of uncinate joints 120 or (b) bonyingrowth in uncinate joints 120 at interfaces between implants 100 andone of cervical vertebrae 184 and 186. In one example of step 438, eachimplant 100 includes at least one void capable of accommodating bonegraft material. Bone graft material may be loaded into the void(s) ofeach implant 100 before or after inserting implant 100 into uncinatejoint 120. In another example of step 438, at least a portion of eachimplant 100 is a porous portion substantially composed of bone graftmaterial. Since the surfaces of uncinate joints 120 are cortical bone,fusion promoted by step 438 may be stronger and/or faster than fusionwithin intervertebral disc space 140.

Without departing from the scope hereof, implant 100 and the distractiontool of step 420 may be integrated, or be the same. In this case, steps420 and 430 may be performed concurrently. An example hereof isdiscussed below in reference to FIGS. 18A-19B.

In certain embodiments, method 400 includes a step 440 of securing eachimplant 100 to the corresponding uncinate joint 120 using additionalhardware. In one example of step 440, a surgeon secures each implant 100to both superior vertebra 184 and inferior vertebra 186 of cervicalspine segment 180. In another example, a surgeon secures each implant100 to only one of superior vertebra 184 and inferior vertebra 186 ofcervical spine segment 180. Step 440 may be performed percutaneously.Exemplary implants compatible with step 440 are discussed in referenceto FIGS. 9A-10B, 13A-15, and 17.

In certain embodiments, method 400 includes a step 450 of monitoring thelocations, within patient 170, of implants 100 and, optionally, otherequipment used to perform one or more of steps 410-440. Step 450 may beperformed during the execution of some or all of steps 410-440. Step 450is an embodiment of step 318. In one embodiment, step 450 includes astep 452 of monitoring locations of implants 100, and optionally otherequipment, relative to vertebral arteries 230 (FIG. 2). Inimplementations of method 400 based upon percutaneous access to uncinatejoints 120, step 450 may include a step 454 of monitoring the locationsof cannulae, guide wires, or other devices providing percutaneous accessto uncinate joints 120.

Without departing from the scope hereof, method 400 may be performedindependently for each of the two uncinate joints 120 of cervical spinesegment 180.

FIGS. 5A and 5B illustrate one exemplary threaded implant 500 forstabilizing uncinate joint 120 (FIG. 1). Threaded implant 500 is anembodiment of implant 100 and may be implemented in method 400 as theself-securing implant of step 433. FIG. 5A shows threaded implant 500 inside elevation. FIG. 5B shows a cross sectional view of threaded implant500, wherein the cross section is taken along line 5B-5B in FIG. 5A.FIGS. 5A and 5B are best viewed together.

Threaded implant 500 has length 580 and diameter 582. Length 580 is atleast six millimeters, for example, to provide sufficient contact areabetween threaded implant 500 and surfaces of uncinate joint 120 thatthreaded implant 500 is capable of supporting the load of uncinate joint120. Length 580 is at most eighteen millimeters, for example, to ensurethat threaded implant 500 does not encroach the neural foramen. Diameter582 may be in the range between two and seven millimeters, to produce aspacing, between superior and inferior surfaces of uncinate joint 120when threaded implant 500 is inserted therein, which is sufficient torelieve impingement issues or pressure on intervertebral disc 150(FIG. 1) while minimizing damage to uncinate joint 120 and allowing forpercutaneous insertion of threaded implant 500. In one example, diameter582 is such that threaded implant 500 may be inserted into uncinatejoint 120 through a cannula.

Threaded implant 500 includes threads 510 along at least a portion oflength 580. Threads 510 have pitch 588 and depth 584. Depth 584 is, forexample, in the range between 0.5 and 1.2 millimeters. Pitch 588 is, forexample, in the range between 0.5 and 2.0 millimeters. Optionally, depth584 and/or pitch 588 changes along the length of threaded implant 500.In one such example, pitch 588 is in the range between 3 and 4millimeters for the full extent of threads 510, but closer to leadingend 520 (the end that first enters uncinate joint 120 when insertingthreaded implant 500 therein) threads 510 include only one set ofthreads while, further from leading end 520, threads 510 include twosets of interlaced threads. Although not shown in FIGS. 5A and 5B,threaded implant 500 may include a non-threaded portion at the trailingend of threaded implant 500 (opposite leading end 520), withoutdeparting from the scope hereof

In one implementation, leading end 520 of threaded implant 500 istapered to ease insertion of threaded implant into uncinate joint 120.In another implementation, at least a portion of threaded implant,extending to leading end 520, is tapered as indicated by dashed lines560 to ease insertion of threaded implant into uncinate joint 120. Inthis implementation, the taper angle 562 may be less than 15°, forexample between 4° and 8°. Taper angle 562 may be configured to matchthe deviation from parallelism between cervical vertebrae 184 and 186 atuncinate joint 120, which stems from the lordosis of the cervical spine.Although FIG. 5A shows optional tapering (as indicated by dashed lines560) as extending along the full length of threaded implant 500,threaded implant 500 may be tapered only along a portion of the lengthof threaded implant 500, without departing from the scope hereof. In onesuch example, a leading end of threaded implant 500 is tapered (asindicated by dashed lines 560) while a trailing end of threaded implant500, adjacent the leading end of threaded implant 500, is not tapered.

In one embodiment, threaded implant 500 is cannulated with athrough-hole 530 extending for the full length 580. Through-hole 530 hasdiameter 586. Diameter 586 may be in the range from 0.5 to 4millimeters. In an exemplary use scenario, threaded implant 500 isthreaded into uncinate joint 120 over a guide wire, wherein the guidewire is passing through through-hole 530.

Although not shown in FIGS. 5A and 5B, threaded implant 500 may includean interface at its trailing end, without departing from the scopehereof. This interface is configured to interface with a driver ordrill, such that this driver or drill threads threaded implant 500 intoplace in uncinate joint 120.

In one embodiment, threaded implant 500 is substantially composed of ametal such as titanium, titanium alloy, stainless steel, cobalt,chromium, or a combination thereof. Without departing from the scopehereof, such metal embodiments of threaded implant 500 may include acoating, for example a hydroxyapatite coating, to achieve improvedfixation of threaded implant 500 to uncinate joint 120. In anotherembodiment, threaded implant 500 includes a porous portion with porescapable of accommodating bone graft material, as discussed in referenceto step 438 of method 400. In one example hereof, threaded implant 500is substantially composed of, or includes, porous metal. In a relatedembodiment, at least a portion of threaded implant 500 is a porousportion substantially composed of bone graft material. In yet anotherembodiment, threaded implant 500 is substantially composed of allograftbone. In a further embodiment, threaded implant 500 is biodegradable orbioabsorbable and is composed, for example, of lactulose, proline,polyglycolic acid or a derivative thereof, poly-L-lactic acid or aderivative thereof, other biodegradable/bioabsorbable materials known inthe art, or a combination thereof. In another embodiment, threadedimplant 500 includes a polymer, such as polyetheretherketone (PEEK) oranother polyaryletherketone (PAEK) polymer. Any of the above materialsmay be used in a 3-D printing process to make threaded implant 500.

FIG. 6A is a diagram 600 showing, in an anterior view, a pair ofthreaded implants 500 (FIGS. 5A and 5B) installed in uncinate joints 120between cervical vertebrae 184 and 186 according to method 400. FIG. 6Bis a close-up of diagram 600 showing one uncinate joint 120 with greaterclarity. FIGS. 6A and 6B are best viewed together. When implemented inmethod 400, each threaded implant 500 is screwed into the correspondinguncinate joint 120 with threads 510 (not shown in FIGS. 6A and 6B)contacting both superior surface 684 and inferior surface 686 ofuncinate joint 120. Threads 510 may grip superior surface 684 andinferior surface 686 and cooperate with a tension band to beself-securing in uncinate joint 120. Threaded implants 500 may beinserted into uncinate joints 120 while leaving intervertebral disc 150intact. Method 400 may utilize optional through-hole 530 to insertthreaded implant into uncinate joint 120 over a guide wire.Alternatively, or in combination therewith, method 400 may utilizeoptional through-hole 530 to carry or accept bone graft material used instep 438 of method 400.

FIGS. 7A and 7B illustrate one exemplary fenestrated, threaded implant700 for stabilizing uncinate joint 120 (FIG. 1). Fenestrated, threadedimplant 700 is an embodiment of threaded implant 500 (FIGS. 5A and 5B)and may be implemented in method 400 as the self-securing implant ofstep 432, as shown in FIGS. 6A and 6B. FIG. 7A shows fenestrated,threaded implant 700 in side elevation. FIG. 7B shows a cross section offenestrated, threaded implant 700, wherein the cross section is takenalong line 7B-7B in FIG. 7A. FIGS. 7A and 7B are best viewed together.

Fenestrated, threaded implant 700 is similar to threaded implant 500 asshown in FIGS. 5A and 5B, except for having fenestrations 720.Fenestrations 720 may serve to accommodate material displaced fromuncinate joint 120 when fenestrated, threaded implant 700 is insertedtherein. Fenestrations 720 may be particularly useful if usingfenestrated, threaded implant 700 as the distraction tool in step 420 ofmethod 400. Alternatively, or in combination therewith, fenestrations720 may be cavities that carry bone graft material with the purpose ofpromoting fusion of uncinate joints 120. Furthermore, edges offenestrations 720 may help secure fenestrated, threaded implant 700 inuncinate joint 120.

Although not shown in FIGS. 7A and 7B, fenestrations 720 may, at leastin places, have depth sufficient to connect with through-hole 530 (ifpresent), or fenestrations 720 may, at least in places, pass throughfenestrated, threaded implant 700 from one side to another opposite sidethereof, without departing from the scope hereof.

FIGS. 8A and 8B illustrate another exemplary fenestrated, threadedimplant 800 for stabilizing uncinate joint 120 (FIG. 1). Fenestrated,threaded implant 800 is an embodiment of threaded implant 500 (FIGS. 5Aand 5B) and may be implemented in method 400 (FIG. 4) as theself-securing implant of step 432, as shown in FIGS. 6A and 6B. FIG. 8Ashows fenestrated, threaded implant 800 in side elevation. FIG. 8B showsa cross section of fenestrated, threaded implant 800, wherein the crosssection is taken along line 8B-8B in FIG. 8A. FIGS. 8A and 8B are bestviewed together.

Fenestrated, threaded implant 800 is similar to fenestrated, threadedimplant 700 (FIGS. 7A and 7B), except for including cavities 830 infenestrations 720. In one embodiment, at least some of cavities 830 arethrough-holes extending between fenestrations 720 located on oppositesides of fenestrated, threaded implant 800. In another embodiment, eachcavity 830 is an separate pocket in fenestrated, threaded implant 800,which does not connect with other cavities 830 or with through-hole 530(if present). In this embodiment, cavities 830 may serve to accommodatebone graft material loaded into cavities 830 prior to insertion offenestrated, threaded implant 800 into uncinate joint 120. Thus, thisembodiment of fenestrated, threaded implant 800 is compatible withembodiments of method 400 that include steps 432 and 438. In yet anotherembodiment, cavities 830 coexist with through-hole 530, and at leastsome of cavities 830 have depth sufficient to reach through-hole 530. Inthis embodiment, a surgeon may load bone graft material intothrough-hole 530, from anterior side 202, after placing fenestrated,threaded implant 800 in uncinate joint 120, whereafter the bone graftmaterial is allowed to contact surfaces of uncinate joint 120 viacavities 830. Thus, this embodiment of fenestrated, threaded implant 800is compatible with embodiments of method 400 that include steps 432 and438.

FIG. 8C illustrates a cap 880 for sealing through-hole 530 offenestrated, threaded implant 800 at the trailing end thereof. Thetrailing end of fenestrated, threaded implant 800 is the end oppositeoptionally tapered leading end 520. The trailing end is associated witha surface 802. Cap 880 may serve, for example in step 438, to seal thetrailing-end portion of through-hole 530 after loading bone graftmaterial into through-hole 530, to prevent bone graft material fromleaking out of the trailing end of through-hole 530. In oneimplementation of method 400, sealing of through-hole 530 at leading end520 is unnecessary since tissue of patient 170 provides resistanceagainst bone graft material leaking out through through-hole 530 atleading end 520.

Cap 880 includes a cylindrical member 882 that fits in through-hole 530.Although not shown in FIGS. 8A-C, and without departing from the scopehereof, cylindrical member 882 and at least a portion of through-hole530 may be threaded, such that a surgeon may screw cap 880 intothrough-hole 530. In one embodiment, cap 880 includes a larger-diameterelement 884 with a surface 886 facing cylindrical member 882. In thisembodiment, surface 886 of cap 880 faces surface 802 of fenestrated,threaded implant 800 when inserting cap 880 into through-hole 530. Asurgeon may insert cap 880 into through-hole 530 to a depth determinedby contact between surfaces 802 and 886.

In one implementation, cap 880 includes a recess 888 having shapematching that of a tool, for example a phillips-head screwdriver/drillor a star-head screwdriver/drill. A surgeon may insert such a tool intorecess 888 to guide, and optionally screw, cylindrical member 882 intothrough-hole 530. In another embodiment, larger-diameter element 884 isshaped to at least partly fit within a tool, such as a hexagonal wrench,thus allowing a surgeon to use a tool to grab onto larger-diameterelement 884 to guide, and optionally screw, cylindrical member 882 intothrough-hole 530.

FIG. 8D illustrates, in side elevation from direction oppositecylindrical member 882 and mounted in through-hole 530 of fenestrated,threaded implant 800, one exemplary cap 880′ which is an implementationof cap 880 that further implements a locking lever. In cap 880′,larger-diameter element 884 is implemented as an oblong element 884′.For example, oblong element 884′is oval, rectangular, or rectangularwith rounded corners. The longer dimension of oblong element 884′extends beyond fenestrated, threaded implant 800 by a distance 850,while the shorter dimension of oblong element 884′ has extent no greaterthan that of fenestrated, threaded implant 800. Optionally, at least aportion of oblong element 884′ extending beyond fenestrated, threadedimplant 800 includes a jagged surface 883. Jagged surface 883 isconfigured to grip a surface of uncinate joint 120 to at leastparticipate in securing fenestrated, threaded implant 800 in uncinatejoint 120. Without departing from the scope hereof, oblong element 884′may extend beyond fenestrated, threaded implant 800 in only onedirection as opposed to the two directions shown in FIGS. 8D.

In one embodiment, cylindrical member 882 of cap 880′ is sized forpressure fit into through-hole 530. Tissue of patient 170 preventsfenestrated, threaded implant 800 from migrating in any other directionthan back out in the posterior-to-anterior direction. Cap 880′, whensecured to uncinate joint 120, prevents fenestrated, threaded implant800 from migrating in the posterior-to-anterior direction, such that cap880′ locks fenestrated, threaded implant 800 in uncinate joint 120. Inan exemplary use scenario, cap 880′ is inserted into through-hole 530(either prior to or after insertion of fenestrated, threaded implant 800into uncinate joint 120) with cap 880′ aligned such that the longerdimension of oblong element 884′ does not interfere with surfaces ofuncinate joint 120. After insertion of cap 880′ into through-hole 530,cap 880′ is rotated about the axis of through-hole 530, for example byabout 45 to about 135 degrees, to secure cap 880′ to one or two surfacesof uncinate joint 120. Optionally, each surface of uncinate joint 120 towhich cap 880′ is secured is prepared, for example by a high-speeddrill, to form a recess for accommodating cap 880′.

FIGS. 8E and 8F show, in an anterior view, fenestrated, threaded implant800 (FIGS. 8A and 8B) with cap 880′ (FIG. 8D) in uncinate joint 120,when installed in uncinate joint 120 according to method 400 (FIG. 4).FIGS. 8E and 8F are best viewed together. In FIG. 8E, cap 880′ is in itsunlocked configuration, after step 436 and before step 437 of method400. In this configuration, fenestrated, threaded implant 800 contactssuperior surface 684 (FIG. 6B) and inferior surface 686, respectively,but oblong member 884′ does not grip either of superior surface 684 andinferior surface 686. In FIG. 8F, cap 880′ is in its lockedconfiguration, after step 437 of method 400. In this configuration, atleast a portion of oblong member 884′ is embedded into each of superiorsurface 684 and inferior surface 686, thus locking the position offenestrated, threaded implant 800 in uncinate joint 120.

FIGS. 9A and 9B illustrate one exemplary shim implant 900 forstabilizing uncinate joint 120 (FIG. 1). Shim implant 900 is anembodiment of implant 100 and may be implemented in method 400 as theimplant of step 436. FIG. 9A shows shim implant 900 in side elevation.FIG. 9B shows a cross section of shim implant 900, wherein the crosssection is taken along line 9B-9B in FIG. 9A. FIGS. 9A and 9B are bestviewed together.

Shim implant 900 has length 980, width 982, and height 984. Length 980is at least six millimeters, for example, to provide sufficient contactarea, between shim implant 900 and surfaces of uncinate joint 120, thatshim implant 900 is capable of supporting the load of uncinate joint120. Length 980 is at most eighteen millimeters, for example, to ensurethat shim implant 900 does not encroach the neural foramen. Width 982may be in the range between two and seven millimeters to providesufficient contact area, between shim implant 900 and surfaces ofuncinate joint 120, while minimizing lateral displacement ofintervertebral disc 150 (FIG. 1). Height 984 may be in the range betweentwo and seven millimeters, to produce a spacing, between superior andinferior surfaces of uncinate joint 120 when shim implant 900 isinserted therein, which is sufficient to relieve impingement issues orpressure on intervertebral disc 150 (FIG. 1), while minimizing damage touncinate joint 120 and allowing for percutaneous insertion of shimimplant 900.

Shim implant 900 has surfaces 924 and 926 configured to contact thesuperior surface and the inferior surface, respectively, of uncinatejoint 120. Shim implant 900 also has a surface 922 configured to be thetrailing surface of shim implant 900, when inserting shim implant 900into uncinate joint 120 according to method 400. Without departing fromthe scope hereof, surfaces 924 and 926, as well as other surfaces ofshim implant 900 may be non-planar. For example, shim implant 900 may betapered, as indicated by dashed lines 960, with a taper angle 962. Taperangle 962 may be less than 15°, for example between 4° and 8°. Taperangle 962 may be configured to match the deviation from parallelismbetween cervical vertebrae 184 and 186 at uncinate joint 120, whichstems from the lordosis of the cervical spine.

Optionally, shim implant 900 is cannulated with through-hole 530extending for the full length 980, such that shim implant 900 may beinserted into uncinate joint 120 over a guide wire.

In one embodiment, shim implant 900 is substantially composed of a metalsuch as titanium, titanium alloy, stainless steel, cobalt, chromium, ora combination thereof. Without departing from the scope hereof, suchmetal embodiments of shim implant 900 may include a coating, for examplea hydroxyapatite coating, on surfaces 924 and 926 to achieve improvedfixation of shim implant 900 to uncinate joint 120. In anotherembodiment, shim implant 900 includes a porous portion with pores thatmay carry bone graft material to uncinate joint 120, as discussed inreference to step 438 of method 400. In one example, surfaces 924 and926 are porous. In another example, shim implant 900 is substantiallycomposed of, or includes, porous metal. In a similar embodiment, thisporous portion is substantially composed of bone graft material thatpromotes bone growth in the pores thereof. In yet another embodiment,shim implant 900 is substantially composed of allograft bone. In afurther embodiment, shim implant 900 includes a polymer. The polymer is,for example, polyetheretherketone (PEEK) or another polyaryletherketone(PAEK) polymer. In a further embodiment, shim implant 900 isbiodegradable or bioabsorbable and is composed, for example, oflactulose, proline, polyglycolic acid or a derivative thereof,poly-L-lactic acid or a derivative thereof, otherbiodegradable/bioabsorbable materials known in the art, or a combinationthereof. Any of the above materials may be used in a 3-D printingprocess to make shim implant 900 .

Although not shown in FIGS. 9A and 9B, shim implant 900 may includehollow portions and associated openings in the surfaces of shim implant900, without departing from the scope hereof. Such hollow portions mayaccommodate bone graft material, as discussed in reference to step 438of method 400.

FIGS. 10A and 10B illustrate, in an anterior view, shim implant 900(FIGS. 9A and 9B) secured to uncinate joint 120 (FIG. 1) using exemplaryadditional hardware, as discussed in reference to step 440 of method 400(FIG. 4). Shim implant 900 is placed in uncinate joint 120 with surfaces924 and 926 contacting superior surface 684 (FIG. 6B) and inferiorsurface 686, respectively, of uncinate joint 120, and with surface 922facing anterior side 202 (FIG. 2).

In FIG. 10A, shim implant 900 is secured to superior cervical vertebra184 by affixing a bracket 1010 to shim implant 900 and superior cervicalvertebra 184. Bracket 1010 may be affixed to shim implant 900 andsuperior cervical vertebra 184 by fasteners 1040 and 1030, respectively.Fastener 1030 is, for example, a screw or a pin. Fastener 1040 is, forexample, a screw or a bolt. In one example, fastener 1040 is configuredto attach to through-hole 530. Through-hole 530 may be threaded. In theimplementation shown in FIG. 10A, surface 926 may be configured to allowrelative movement between inferior surface 686 and surface 926, suchthat shim implant 900 is motion-preserving. Alternatively, surface 926is textured to grip inferior surface 686, thus fixing inferior surface686 with respect to superior surface 684.

In one example of the implementation shown in FIG. 10A, shim implant 900includes voids at the interface with superior cervical vertebra 184.These voids are capable of accommodating bone graft material to promotebony ingrowth at this interface. The voids may be connected withthrough-hole 530, such that bone graft material may be loaded into thevoids via through-hole 530 from anterior side 202 when shim implant 900is located in uncinate joint 120. Fastener 1040, optionally incooperation with bracket 1010, may function as a cap for sealingthrough-hole 530, to prevent leakage of bone graft material out of thetrailing end of through-hole 530.

Without departing from the scope hereof, shim implant 900 may be mountedvia bracket 1010 to inferior cervical vertebra 186 instead of superiorcervical vertebra 184. Additionally, bracket 1010 may have shapedifferent from that shown in FIG. 10A.

In FIG. 10B, shim implant 900 is secured to both superior cervicalvertebra 184 and inferior cervical vertebra 186 by affixing a bracket1050 to shim implant 900, superior cervical vertebra 184, and inferiorcervical vertebra 186. Bracket 1050 may be affixed to shim implant 900,superior cervical vertebra 184, and inferior cervical vertebra 186 byfasteners 1040, 1030, and 1030, respectively, as discussed above inreference to FIG. 10A.

In one example of the implementation shown in FIG. 10B, shim implant 900includes voids, at least at the interfaces with cervical vertebrae 184and 186. These voids are capable of accommodating bone graft material topromote fusion of uncinate joint 120. The voids may be connected withthrough-hole, such that bone graft material may be loaded into the voidsvia through-hole 530 from anterior side 202 when shim implant 900 islocated in uncinate joint 120. Fastener 1040, optionally in cooperationwith bracket 1050, may function as a cap for sealing through-hole 530,to prevent leakage of bone graft material out of through-hole 530, asdiscussed in reference to FIG. 8C.

FIGS. 11A, 11B, and 11C illustrate one exemplary locking implant 1100for stabilizing uncinate joint 120 (FIG. 1). Locking implant 1100 is anembodiment of implant 100 and may be implemented in method 400 (FIG. 4)as the implant of steps 436 and 437. FIG. 11A shows locking implant 1100in side elevation. FIGS. 11B and 11C show a front elevation view ofleading end 1130 of locking implant 1100, wherein leading end 1130 isthe end of locking implant 1100 that first enters uncinate joint 120when inserting locking implant 1100 into uncinate joint 120 according tomethod 400. In FIGS. 11A and 11B, locking implant 1100 is in itsunlocked configuration. In FIG. 11C, locking implant 1100 is in itslocked configuration. FIGS. 11A, 11B, and 11C are best viewed together.

Locking implant 1100 includes a body 1110 that is similar to shimimplant 900 (FIG. 9). Body 1110 may be tapered as discussed in referenceto shim implant 900. Body 1110 has surfaces 1124 and 1126 configured toface superior surface 684 (FIG. 6B) and inferior surface 686,respectively, of uncinate joint 120, when locking implant 1100 is placedin uncinate joint 120. At leading end 1130, locking implant 1100 furtherincludes a locking lever 1120 attached to body 1110.

Locking implant 1100 has a longer dimension 1140 and a shorter dimension1142. Shorter dimension 1142 is such that, when locking implant 1100 isin its unlocked configuration (see FIG. 11B), locking lever 1120 doesnot extend beyond surfaces 1124 and 1126. Longer dimension 1140 is suchthat, when locking implant 1100 is in its locked configuration (see FIG.11C), locking lever 1120 extends beyond each of surfaces 1124 and 1126by a distance 1150. Distance 1150 is, for example, in the range between0.2 and 1.0 millimeters. The cross section of locking lever 1120 may beoval (as shown in FIGS. 11B and 11C), rectangular, or otherwiseelongated to meet these requirements to longer dimension 1140 andshorter dimension 1142. Locking implant 1100 includes a rotationmechanism 1125 coupled with locking lever 1120. Rotation mechanism 1125is accessible from trailing end 1132 of locking implant 1100. Whenactuated, rotation mechanism 1125 rotates locking lever 1120, forexample from its unlocked position (FIG. 11B) to its locked position(FIG. 11C).

In one embodiment, locking implant 1100 is cannulated with athrough-hole 1160 extending from leading end 1130 to trailing end 1132.Method 400 may utilize through-hole 1160 to insert locking implant 1100into uncinate joint 120 over a guide wire, as discussed in reference toFIG. 4.

Rotation mechanism 1125 may be implemented in a shaft 1128 rigidlycoupled to locking lever 1120. Shaft 1128 may implement rotationmechanism 1125 as a receptacle for a driver, such that rotation of thedriver, when engaged with the receptable, results in rotation of lockinglever 1120. The receptacle may be male or female or a combinationthereof. Shaft 1128 may implement a portion of through-hole 1160.

Optionally, locking implant 1100 includes two or more locking levers1120. In one example, a second locking lever 1120 is located at trailingend 1132. Rotation mechanism 1125 may be coupled with all locking levers1120 of locking implant 1100 to simultaneously rotate all locking levers1120. In embodiments including two or more locking levers 1120, alllocking levers 1120 may be rigidly interconnected (for example via shaft1128) and rotation mechanism 1125 may be integrated in one of lockinglevers 1120 as a receptacle for a driver, such that the driver, whenacting on rotation mechanism 1125, rotates all locking levers 1120 inthe same manner. The receptacle may be male or female or a combinationthereof.

Without departing from the scope hereof, locking implant 1100 mayinclude a locking lever 1120 only at trailing end 1132. In such anembodiment, rotation mechanism 1125 may be integrated in locking lever1120 as a receptacle for a driver. The receptacle may be male or femaleor a combination thereof

In one embodiment, locking implant 1100 is substantially composed of ametal such as titanium, titanium alloy, stainless steel, cobalt,chromium, or a combination thereof. Without departing from the scopehereof, such metal embodiments of locking implant 1100 may include acoating, for example a hydroxyapatite coating, on surfaces 1124 and 1126and/or on locking lever(s) 1120 to achieve improved fixation of lockingimplant 1100 to uncinate joint 120. In another embodiment, lockingimplant 1100 includes a porous portion with pores that may carry bonegraft material to uncinate joint 120, as discussed in reference to step438 of method 400. For example, surfaces 1124 and 1126, or all of body1110, may be porous. Surfaces 1124 and 1126, or all of body 1110, may beporous metal. In a similar embodiment, the porous portion issubstantially composed of bone graft material that promotes bone growthin the pores thereof. In yet another embodiment, body 1110 issubstantially composed of allograft bone. Although not shown in FIGS.11A, 11B, and 11C, body 1110 may include hollow portions and associatedopenings in the surfaces of body 1110, without departing from the scopehereof. Such hollow portions may carry bone graft material, as discussedin reference to step 438 of method 400. In a further embodiment, lockingimplant 1100 is biodegradable or bioabsorbable and is composed, forexample, of lactulose, proline, polyglycolic acid or a derivativethereof, poly-L-lactic acid or a derivative thereof, otherbiodegradable/bioabsorbable materials known in the art, or a combinationthereof. Any of the above materials may be be used in a 3-D printingprocess to make body 1110.

FIG. 11D illustrates one exemplary implementation of locking lever 1120that includes a jagged surface 1170 on at least on a portion of lockinglever 1120 configured to contact superior surface 684 and inferiorsurface 686.

FIG. 11E illustrates another exemplary implementation of locking lever1120, wherein locking lever extends beyond only one of surfaces 1124 and1126 when in locked position. In this implementation, locking implant1100 is configured such that locking lever 1120 contacts only one ofsuperior surface 684 and inferior surface 686. Although not shown inFIG. 11E, the portion of locking lever 1120, which is configured tocontact one of superior surface 684 and inferior surface 686, may bejagged as shown in FIG. 11D.

FIGS. 12A and 12B show, in a posterior view, locking implant 1100 (FIGS.11A-E) in uncinate joint 120, when installed in uncinate joint 120according to method 400 (FIG. 4). FIGS. 12A and 12B are best viewedtogether. In FIG. 12A, locking implant 1100 is in its unlockedconfiguration, after step 436 and before step 437 of method 400. In thisconfiguration, surfaces 1124 and 1126 contact superior surface 684 (FIG.6B) and inferior surface 686, respectively, but locking lever 1120 doesnot contact either of superior surface 684 and inferior surface 686. InFIG. 12B, locking implant 1100 is in its locked configuration, afterstep 437 of method 400. In this configuration, at least a portion oflocking lever 1120 is embedded into each of superior surface 684 andinferior surface 686, thus locking the position of locking implant 1100in uncinate joint 120.

FIGS. 13A, 13B, 13C, and 13D illustrate one exemplary motion-preservingimplant 1300 for stabilizing uncinate joint 120 (FIG. 1).Motion-preserving implant 1300 is an embodiment of implant 100 and maybe implemented in method 400 as the implant of step 434. FIG. 13A showsmotion-preserving implant 1300 in side elevation. FIG. 13B showsmotion-preserving implant 1300 in cross-sectional view, wherein thecross section is taken along line 13B-13B in FIG. 13A. FIG. 13C showsleading end 1330 of motion-preserving implant 1300 in elevation view,while FIG. 13D shows trailing end 1332 of motion-preserving implant 1300in elevation view. Leading end 1330 is the end that first entersuncinate joint 120 when inserting motion-preserving implant 1300 intouncinate joint 120 according to method 400. FIGS. 13A-D are best viewedtogether.

Motion-preserving implant 1300 includes a screw 1310 with threads 1312.Threads 1312 may be similar to threads 510 (FIG. 5). Motion-preservingimplant 1300 further includes a housing 1320 that partly contains screw1310. Screw 1310 protrudes, by a distance 1386, through an opening 1324of housing 1320, such that threads 1312 may contact a surface ofuncinate joint 120. Distance 1386 is, for example, around one millimeteror a fraction of a millimeter. Distance 1386 may be such that housing1320 contacts the surface of uncinate joint 120. Housing 1320 includes asurface 1322 that is able to slide on a surface of uncinate joint 120.In one example, surface 1322 is smooth. Surface 1322 may be curved toaccommodate a variety of angles between surface 1322 and a surface ofuncinate joint 120 in contact with surface 1322. Surface 1322 generallyfaces away from opening 1324. Motion-preserving implant 1300 furtherincludes a rotation mechanism 1315 that, when actuated, rotates screw1310. Rotation mechanism 1315 may be accessible from trailing end 1332.In one embodiment, rotation mechanism 1315 is a recess configured toaccept a driver or drill, for example a hex driver or drill, such thatthis driver or drill may rotate screw 1310.

Motion-preserving implant 1300 has length 1380, width 1382, and height1384, which may be similar to length 980, width 982, and height 984 ofshim implant 900 (FIGS. 9A and 9B).

Optionally, motion-preserving implant 1300 is cannulated with athrough-hole 1360 extending from leading end 1330 to trailing end 1332.Method 400 may utilize through-hole 1360 to insert motion-preservingimplant 1300 into uncinate joint 120 over a guide wire, as discussed inreference to FIG. 4. Through-hole 1360 is centered relative to the crosssection of screw 1310, such that screw 1310 may rotate whilemotion-preserving implant 1300 is placed over a guide wire.

Screw 1310 may be of similar material and/or structural composition asthreaded implant 500 (FIGS. 5A and 5B). Housing 1320 may be of similarmaterial and/or structural composition as shim implant 900.

Without departing from the scope hereof, housing 1320 may be tapered. Inone example, housing 1320 is tapered, as indicated by dashed line 1370,with a taper angle 1372. Taper angle 1372 may be less than 15°, forexample between 4° and 8°. Taper angle 1372 may be configured to matchthe deviation from parallelism between cervical vertebrae 184 and 186 atuncinate joint 120, which stems from the lordosis of the cervical spine.In another example, housing 1320 is curved and tapered, such that curvedsurface 1322 has orientation generally along dashed line 1370.

FIG. 14A shows, in an anterior view, a pair of motion-preservingimplants 1300 (FIGS. 13A-D) installed in uncinate joints 120 accordingto method 400 (FIG. 4). FIG. 14B is a close-up of FIG. 14A showing oneuncinate joint 120 in further detail. FIGS. 14A and 14B are best viewedtogether.

When inserting motion-preserving implant 1300 into correspondinguncinate joint 120, in step 434 of method 400, motion-preserving implant1300 is oriented such that screw 1310 contacts superior surface 684(FIG. 6B), while surface 1322 contacts inferior surface 686. A surgeonrotates screw 1310 using rotation mechanism 1315 (for clarity not shownin FIGS. 14A and 14B). Since screw 1310 contacts superior surface 684,this rotation screws motion-preserving implant 1300 into uncinate joint120. Surface 1322 contacts inferior surface 686 while allowing relativemovement between motion-preserving implant 1300 and inferior surface686.

FIG. 15 shows, in an anterior view, motion-preserving implant 1300(FIGS. 13A-D) secured to uncinate joint 120 (FIG. 1) using exemplaryadditional hardware, as discussed in reference to step 440 of method 400(FIG. 4). Motion-preserving implant 1300 is located in uncinate joint120 with screw 1310 contacting and gripping superior surface 684 (FIG.6B). Motion-preserving implant 1300 is secured to superior cervicalvertebra 184 by affixing a bracket 1510 to motion-preserving implant1300 and superior cervical vertebra 184. Bracket 1510 may be affixed tomotion-preserving implant 1300 and superior cervical vertebra 184 byfasteners 1540 and 1530, respectively. Fastener 1530 is, for example, ascrew or a pin. Fastener 1540 is, for example, a screw or a bolt. In oneexample, fastener 1540 is configured to attach to through-hole 1360.Without departing from the scope hereof, bracket 1510 may have shapedifferent from that shown in FIG. 15.

FIGS. 16A, 16B, 16C, and 16D illustrate one exemplary bracket 1600 forsecuring two implants 100, located in uncinate joints 120 of cervicalspine segment 180 (FIG. 1), to one vertebra of cervical spine segment180. Bracket 1600 is common to both implants 100. FIGS. 16A-D show ascenario, wherein bracket 1600 secures a pair of motion-preservingimplants 1300 (FIGS. 13A-D) to cervical spine segment 180. However,bracket 1600 may be applied to other embodiments of implant 100, such asshim implant 900 (FIGS. 9A and 9B) and screw-in implant 1700 discussedbelow in reference to FIGS. 17A-D. Method 400 (FIG. 4) may implementbracket 1600 in step 440.

FIG. 16A shows, in an anterior view, a pair of motion-preservingimplants 1300 (FIGS. 13A-D) secured to uncinate joints 120 (FIG. 1)using bracket 1600. FIG. 16B shows bracket 1600 in side elevation view,separate from cervical spine segment 180. Each of FIGS. 16C and 16Dshows bracket 1600 in perspective view, separate from cervical spinesegment 180. FIGS. 16A-D are best viewed together.

Bracket 1600 includes a half-bracket 1610 and a half-bracket 1620. Eachof half-brackets 1610 and 1620 is attached to one motion-preservingimplant 1300 by a fastener 1630. Fastener 1630 is, for example, a boltor a screw. Each of half-brackets 1610 and 1620 has a slot 1640configured to accept a screw 1650. Screw 1650 secures half-brackets 1610and 1620 to an anterior surface of the vertebral body of superiorcervical vertebra 184. The shape of half-brackets 1610 and 1620 may bedifferent from those shown in FIGS. 16A-D, without departing from thescope hereof.

Although FIGS. 14-16D illustrate a configuration whereinmotion-preserving implant 1300 is secured to superior cervical vertebra184, motion-preserving implant 1300 may be inserted into uncinate joint120 with screw 1310 contacting inferior surface 686 and with surface1322 facing superior surface 684, such that motion-preserving implant1300 may be secured to inferior cervical vertebra 186, without departingfrom the scope hereof.

FIGS. 17A, 17B, 17C, and 17D illustrate one exemplary screw-in implant1700 for stabilizing uncinate joint 120 (FIG. 1). Screw-in implant 1700is similar to motion-preserving implant 1300 (FIGS. 13A-D) except thatscrew-in implant 1700 includes fenestrations 1722 that at least helpsecure screw-in implant 1700 to the surface of uncinate joint 120opposite the surface of uncinate joint interfacing with screw 1310.Thus, screw-in implant 1700 is configured to fix motion of uncinatejoint 120. Additionally, screw-in implant 1700 may include an accessport 1760 that accepts bone graft material into screw-in implant 1700from its trailing end 1332. FIG. 17A shows screw-in implant 1700 in sideelevation. FIG. 17B shows screw-in implant 1700 in cross-sectional view,wherein the cross section is taken along line 17B-17B in FIG. 17A. FIG.17C shows trailing end 1332 of screw-in implant 1700 in elevation view.FIG. 17D shows a fenestrated surface of screw-in implant 1700. FIGS.17A-D are best viewed together.

As compared to motion-preserving implant 1300, screw-in implant 1700includes a housing 1720 instead of housing 1320. Housing 1720 is similarto housing 1320, except that surface 1322 in housing 1720 includesfenestrations 1722. For clarity of illustration, not all fenestrations1722 are labeled in FIGS. 17A-D. FIG. 17C shows surface 1322.Fenestrations 1722 may aid in securing screw-in implant 1700 to uncinatejoint 120 through friction between fenestrations 1722 and an associatedone of superior surface 684 and inferior surface 686.

In one embodiment, each fenestration 1722 is wider (in dimensionassociated with width 1382) closer to leading end 1330 and narrowercloser to trailing end 1332. This shape may result in greater frictionagainst lateral movement and posterior-to-anterior movement of surface1322 in uncinate joint 120 than the friction between surface 1322 anduncinate joint 120 associated with insertion of screw-in implant 1700along anterior-to-posterior direction 210 (FIG. 2). However, the shapeof fenestration 1722 may differ from that shown in FIG. 17C, withoutdeparting from the scope hereof. Likewise, the number of fenestrations1722, and/or the pattern in which fenestrations 1722 are arranged, maybe different from what is shown in FIGS. 17A-C.

In one implementation, screw-in implant 1700 is self-securing by virtueof threads 1312. In another implementation, screw-in implant 1700 issecured to cervical spine segment 180 using a mounting bracket, andassociated fasteners. In one example, screw-in implant 1700 is securedto cervical spine segment 180 using bracket 1510 (FIG. 15), bracket 1050(FIG. 10B), or bracket 1600 (FIGS. 16A-D). In another example, screw-inimplant 1700 is secured to cervical spine segment 180 using two brackets1600 with one bracket secured to superior vertebra 184 and the otherbracket secured to inferior vertebra 186.

In one exemplary scenario, screw-in implant 1700 is implemented inmethod 400 according to an embodiment of method 400, which includes step434 and 438. In this scenario, bone graft material is loaded intohousing 1720 and allowed to contact both superior surface 684 andinferior surface 686 (FIG. 6B) of uncinate joint 120 throughfenestrations 1722 and opening 1324. In one implementation of step 438,bone graft material is loaded into housing 1720 prior to insertion ofscrew-in implant 1700 into uncinate joint 120. In another implementationof step 438, bone graft material is loaded into housing 1720 afterinsertion of screw-in implant 1700 into uncinate joint 120. In thisimplementation, bone graft material may be loaded into housing 1720 attrailing end 1332 via through-hole 1360, and with screw 1310 implementedwith fenestrations that connect through-hole 1360 to an external surfaceof screw 1310 (as discussed in reference to fenestrated, threadedimplant 800 (FIGS. 8A-D). Optionally, through-hole 1360 is subsequentlysealed with a cap. In one example, sealing is accomplished by a mountingbracket, and/or associated fastener, used to secure screw-in implant1700 to cervical spine segment 180. Such sealing may be accomplishedusing (a) fastener 1540 (FIG. 15) optionally with bracket 1510, (b)fastener 1040 optionally with bracket 1050 (FIG. 10B), or (c) fastener1630 (FIGS. 16A-D) optionally with bracket 1600. In yet anotherimplementation of step 438, bone graft material is loaded into housing1720, via an access port 1760, after insertion of screw-in implant 1700into uncinate joint 120. Access port 1760 may be subsequently sealedusing a cap.

Without departing from the scope hereof, screw-in implant 1700 may beconfigured to allow for removal of screw 1310, along aposterior-to-anterior direction, when screw-implant 1700 is in place inuncinate joint 120. In this case, bone graft material may be loaded intohousing 1720 after removal of screw 1310.

FIGS. 18A-D illustrate one exemplary implant system 1800 including (a)one exemplary implant 1810 for stabilizing uncinate joint 120 (FIG. 1)and (b) one exemplary screw 1820 for inserting implant 1810 intouncinate joint 120. Implant system 1800 is associated with alongitudinal axis 1860. Longitudinal axis 1860 is generally orientedalong anterior-to-posterior direction 210 (FIG. 2) when implant system1800 is located in uncinate joint 120. FIGS. 18A and 18B show implantsystem 1800 in mutually orthogonal side elevation views, both orthogonalto longitudinal axis 1860. FIG. 18C shows implant system 1800 incross-sectional view, wherein the cross section is taken along line18C-18C in FIG. 18B. FIG. 18D shows one example of implant system 1800in the same view as used for FIG. 18B. FIGS. 18A-D are best viewtogether. Implant system 1800 is configured to insert implant 1810 intouncinate joint 120 along anterior-to-posterior direction 210. Implantsystem 1800 and implant 1810 may be implemented in method 400 (FIG. 4).

Implant system 1800 has a leading end 1830 that enters uncinate joint120 first, when inserting implant system 1800 into uncinate joint 120.Opposite leading end 1830, implant system has a trailing end 1832.Implant 1810 has an elongated cross section in the plane orthogonal tolongitudinal axis 1860 (see FIG. 18C). For example, implant 1810 isoval, rectangular, or rectangular with rounded corners. The crosssection of screw 1820 is circular in the plane orthogonal tolongitudinal axis 1860. Screw 1820 includes threads 1822. Threads 1822may have properties similar to threads 510 of threaded implant 500(FIGS. 5A and 5B).

FIG. 18A shows implant system 1800 in an orientation associated with aminimum extent 1870 of implant 1810 in the plane orthogonal tolongitudinal axis 1860. FIG. 18B shows implant system 1800 in anorientation associated with a maximum extent 1872 of implant 1810 in theplane orthogonal to longitudinal axis 1860. Screw 1820 has diameter 1874that is greater than minimum extent 1870 and less than maximum extent1872. Thus, in the dimension associated with minimum extent 1870,threads 1822 protrude from implant 1810, while in the dimensionassociated with maximum extent 1872, screw 1820 is enclosed by implant1810.

Implant 1810 includes a rough surface 1812 on at least on a portion ofimplant 1810 configured to contact superior surface 684 and inferiorsurface 686 when implant 1810 is placed in uncinate joint 120. Forclarity of illustration, rough surface 1812 is not indicated in FIGS.18A and 18B. Rough surface 1812 may include fenestrations, protrudingfeatures, surface texture, or other elements to form rough surface 1812.

Implant system 1800 further includes interfaces 1840 and 1850, locatedat trailing end 1832. A surgeon may couple a tool 1890 to interfaces1840 and 1850 to rotate implant 1810 and screw 1820, respectively, aboutlongitudinal axis 1860. Tool 1890 and interfaces 1840 and 1850 areconfigured such that the surgeon may rotate screw 1820 independently ofimplant 1810. Without departing from the scope hereof, one or both ofinterfaces 1840 and 1850 may include functionality to rotate implant1810 and screw 1820 in response to actuation by tool 1890. Tool 1890 mayinclude two different tools respectively configured to interface withinterfaces 1840 and 1850. In one embodiment, interface 1840 is nested ininterface 1850 and/or protrudes interface 1840. In this embodiment, thetool configured to interface with interface 1850 fits over interface1840, and optionally also over the tool configured to interface withinterface 1840. FIG. 18D shows one such example of implant system 1800,wherein interface 1850 is an extension of implant 1810 away from leadingend 1830, and interface 1840 is a shaft coupled to screw 1820 andextending through interface 1850 in the direction away from leading end1830. In an alternate embodiment, 1850 has an opening for inserting atool therethrough to engage with an interface 1840 closer than interface1850 to leading end 1830.

Although not shown in FIGS. 18A and 18B, one or both of implant 1810 andscrew 1820 may be tapered, as discussed for threaded implant 500 (FIGS.5A and 5B), without departing from the scope hereof.

FIGS. 19A and 19B illustrate, in a posterior view, insertion of implant1810 (FIGS. 18A-D), using implant system 1800, into uncinate joint 120(FIG. 1) along anterior-to-posterior direction 210 (FIG. 2) according tomethod 400 (FIG. 4). Implant system 1800 may perform steps 420 and 430of method 400. FIGS. 19A and 19B are best viewed together.

FIG. 19A shows implant system 1800 during insertion of implant system1800 into uncinate joint 120 along anterior-to-posterior direction 210.During this operation, the surgeon operates tool 1890 (not shown inFIGS. 19A and 19B) to orient implant 1810 such that threads 1822 ofscrew 1820 are in contact with superior surface 684 (FIG. 6B) andinferior surface 686 of uncinate joint 120. The surgeon operates tool1890 to rotate screw 1820 to screw implant system 1800 into uncinatejoint 120. When implant system 1800 is in a location within uncinatejoint 120, suitable for stabilizing uncinate joint 120 using implant1810, the surgeon uses tool 1890 to rotate implant 1810, such that roughsurfaces 1812 grip superior surface 684 and inferior surface 686 (seeFIG. 19B). This operation secures implant 1810 to uncinate joint 120.Additionally, this operation may serve to distract uncinate joint 120 toincrease the spacing between superior surface 684 and inferior surface686. In turn, increasing the spacing between superior surface 684 andinferior surface 686 may relieve pathological issues in cervical spinesegment 180, such as nerve impingement or damage to intervertebral disc150. In one exemplary scenario, the spacing between superior surface 684and inferior surface 686 is increased by one or several millimeters,when implant 1810 is rotated as shown in FIG. 19B.

After rotating implant 1810, as shown in FIG. 19B, the surgeon may usetool 1890 to back screw 1820 out of uncinate joint 120, along aposterior-to-anterior direction, while leaving implant 1810 in uncinatejoint 120. Subsequently, the surgeon may load bone graft material intoimplant 1810 from trailing end 1832, and optionally seal trailing end1832 with a cap, similar to the cap shown in FIG. 8C.

FIG. 20 illustrates one exemplary method 2000 for stabilizing uncinatejoints 120 (FIG. 1) of cervical spine segment 180, using access touncinate joints 120 via medial-to-lateral directions 220 (FIG. 2).Method 2000 is an embodiment of method 300 (FIG. 3).

In a step 2010, at least an anterior portion of intervertebral discspace 140 is opened to gain access to uncinate joints 120 viamedial-to-lateral directions 220. Step 2010 may utilize methods known inthe art. For example, a surgeon may access intervertebral disc space 140by (a) making a skin incision in the front of the neck, (b) making atunnel to the spine by moving aside muscles and retracting the trachea,esophagus, and arteries, and (c) lifting and holding aside the musclesthat support the front of the spine. Optionally, the surgeon screws pinsinto both superior cervical vertebra 184 and inferior cervical vertebra186 and uses these pins to distract intervertebral disc space 140.

In a step 2020, for each uncinate joint 120, implant 100 is insertedinto uncinate joint 120 from intervertebral disc space 140 alongmedial-to-lateral directions 220. Exemplary implants compatible with usein step 2020 are discussed below in reference to FIGS. 23A-26. In oneembodiment, step 2020 includes a step 2022 of using an actuator coupledwith implants 100 to insert implants 100 into uncinate joints 120. Inone example of step 2022, a surgeon uses an actuator, holding a pair ofimplants 100, to insert implants 100 into uncinate joints 120 fromintervertebral disc space 140. One exemplary actuator is discussed belowin reference to FIGS. 27 and 28. Optionally, step 2020 includes a step2024 of loading bone graft material with, or into, implants 100 topromote fusion of uncinate joints 120. In one example of step 2024, eachimplant 100 used in step 2020 has at least one void capable ofaccommodating bone graft material. Bone graft material may be loadedinto the void(s) of each implant 100 before or after inserting implant100 into uncinate joint 120. In another example of step 2024, at least aportion of each implant 100 is a porous portion substantially composedof bone graft material.

In a step 2030, implants 100, inserted into uncinate joints 120 in step2020, are at least temporarily secured to respective uncinate joints120. Step 2030 may be an integrated element of step 2020. Step 2030 mayutilize self-securing embodiments of implants 100 or utilize additionalhardware to secure implants 100 in uncinate joints 120. In oneembodiment, step 2030 includes a step 2032 of, for each uncinate joint120, utilizing one or more protruding features of implant 100 to grip atleast one of superior surface 684 (FIG. 6B) and inferior surface 686,and thus at least temporarily securing implant 100 in uncinate joint120. Exemplary protruding features include barbs, ribs, and surfacetexture. Exemplary implants compatible with step 2032 are discussedbelow in reference to FIGS. 23A-D, 25, and 29. Step 2030 may include astep 2034, wherein a tension band is utilized to secure each implant 100to the corresponding uncinate joint 120. Steps 2032 and 2034 may beimplemented in combination. Although not shown in FIG. 20, the actuatorof step 2022 may remain coupled to implants 100 during step 2030, suchthat the actuator at least participates in securing implants 100 inuncinate joints 120.

In a step 2040, method 2000 performs cervical discectomy to removeintervertebral disc 150, or at least the majority thereof, fromintervertebral disc space 140. Step 2040 may utilize methods and toolsknown in the art. Since implants 100 are located in uncinate joints 120,implants 100 prevent the surgeon from accidentally damaging thevertebral arteries 230 of patient 170. In one embodiment, step 2040utilizes at least one of implants 100 located in uncinate joints 120,and includes a step 2042 of securing at least a portion of theequipment, used to perform the cervical discectomy, to implants 100. Inone example of step 2042, at least one of implants 100 is coupled withan extension that extends outside the corresponding uncinate joint 120in an anterior direction, and cervical discectomy equipment is attachedto this at least one extension. For example, a soft-tissue retractor,used to retract soft tissue of the neck, may be attached to at least oneimplant 100 or extension thereof. Exemplary extensions are discussedbelow in reference to FIG. 28.

In one embodiment, method 2000 further includes a step 2050 subsequentto step 2040. In step 2050, an IVDS implant is inserted intointervertebral disc space 140. In one embodiment, the IVDS implant is anartificial disc device configured to preserve motion of cervical spinesegment 180. In this embodiment, implants 100 may be motion-preservingas well or, alternatively, implants 100 are biodegradable/bioabsorbableand, after some time, cease to play a role in the mobility of cervicalspine segment 180. In another embodiment, step 2050 promotes fusion ofcervical spine segment 180 within intervertebral disc space 140. In thisembodiment, step 2050 includes a step 2052 of loading bone graftmaterial with, or into, the IVDS implant. Method 2000 may implement step2052 together with step 2024 to achieve fusion strength and/or speedsuperior to that possible when fusing only intervertebral disc space140. In one example, steps 2050 and 2052 utilize an IVDS implant that isa rigid structure with at least one void capable of accommodating bonegraft material. The void(s) may be loaded with bone graft material priorto or after insertion of the IVDS implant into intervertebral disc space140. In another example, steps 2050 and 2052 utilize an IVDS implantthat is or includes a porous element substantially composed of bonegraft material. In yet another example, the IVDS implant of steps 2050and 2052 is a bag with bone graft material. The use of a non-rigid IVDSimplant, such as a bag, in step 2050 is facilitated by stabilizinguncinate joints 120 through steps 2020 and 2030.

In certain embodiments, the IVDS implant of step 2050 is not loadbearing in cervical spine segment 180, or carries only a fraction of theload. These embodiments are facilitated by the load bearing capacity ofimplants 100 inserted into uncinate joints 120 in step 2020. This is incontrast to conventional intervertebral cages that must be configured tocarry the load of cervical spine segment 180, which imposes significantrequirements on how the conventional intervertebral cages contactcervical vertebrae 184 and 186. In comparison, a non-load bearing orpartial-load bearing IVDS implant, used in step 2050, may have lesscontact area with cervical vertebrae 184 and 186, for example.

Optionally, step 2050 is followed by a step 2060 of securing implants100 (inserted into uncinate joints 120 in step 2020) using, at least inpart, mechanical coupling with an IVDS implant inserted intointervertebral disc space 140 in step 2052. For example, this IVDSimplant may contact implants 100 to prevent implants 100 from migratingtowards intervertebral disc space 140. In one exemplary scenario,intervertebral disc 150 participates in the tension band of step 2034.After cervical discectomy in step 2040, the tension band may be loosenedand it may be preferred to employ additional measures to secure implants100 in uncinate joints 120. Step 2060 serves to provide such measures.FIGS. 29-31, discussed below, illustrate one exemplary embodiment ofimplant 100 and one exemplary IVDS implant, which are compatible withstep 2060. Without departing from the scope hereof, step 2052 may beperformed after step 2060. Step 2060 may utilize a non-load bearing orpartial-load bearing IVDS implant.

FIG. 21 illustrates one exemplary method 2100 for stabilizing uncinatejoints 120 of cervical spine segment 180 (FIG. 1) at least whileperforming cervical discectomy. Method 2100 accesses uncinate joints 120from intervertebral disc space 140 along medial-to-lateral directions220 (FIG. 2). Method 2100 is an embodiment of method 300 (FIG. 3), whichutilizes temporary trial implants for at least a portion of theprocedure. Trial implants are embodiments of implant 100 configured tobe removable.

In a step 2110, at least an anterior portion of intervertebral discspace 140 is opened to gain access to uncinate joints 120 viamedial-to-lateral directions 220. Step 2110 is similar to step 2010 ofmethod 2000 (FIG. 20).

In a step 2120, each uncinate joint 120 is distracted by inserting atrial implant into uncinate joint 120 from intervertebral disc space 140along medial-to-lateral direction 220. In one example of step 2120, asurgeon inserts a removable embodiment of implant 100 into each uncinatejoint 120 from intervertebral disc space 140 along medial-to-lateraldirection 220. Exemplary implants compatible with use in step 2020 arediscussed below in reference to FIGS. 23A-26.

In a step 2130, the trial implants of step 2120 are temporarily securedin uncinate joints 120. Step 2130 may be an integrated element of step2120. Step 2130 may utilize self-securing embodiments of implants 100.In one embodiment, step 2130 includes a step 2132 of, for each uncinatejoint 120, utilizing one or more protruding features of implant 100 togrip at least one of superior surface 684 (FIG. 6B) and inferior surface686, and thus temporarily securing the trial implant in uncinate joint120. Exemplary protruding features include barbs, ribs, and surfacetexture. Exemplary implants compatible with step 2132 are discussedbelow in reference to FIGS. 23A-D, 25, and 29. Step 2130 may include astep 2134, wherein a tension band is utilized to secure each trialimplant to the corresponding uncinate joint 120. Steps 2132 and 2134 maybe implemented in combination.

In a step 2140, method 2100 performs cervical discectomy to removeintervertebral disc 150, or at least the majority thereof, fromintervertebral disc space 140. Step 2140 may utilize methods and toolsknown in the art. Since the trial implants are located in uncinatejoints 120, the trial implants prevent the surgeon from accidentallydamaging the vertebral arteries 230 of patient 170. In one embodiment,step 2140 utilizes at least one of the trial implants located inuncinate joints 120, and includes a step 2142 of securing at least aportion of the equipment, used to perform the cervical discectomy, tothis at least one trial implant. In one example of step 2142, at leastone of the trial implants, or an extension coupled therewith, extendsoutside the corresponding uncinate joint 120 in an anterior direction,and cervical discectomy equipment is attached to this at least one trialimplant or extension thereof. For example, a soft-tissue retractor, usedto retract soft tissue of the neck, may be attached to at least onetrial implant or extension thereof. Exemplary extensions are discussedbelow in reference to FIG. 28.

In a step 2150, the trial implants are removed from uncinate joints 120.The trial implants may be removed using methods known in the art. Step2150 may include pulling out the trial implants using plier-type toolsand/or tapping out the trial implants. Step 2150 may include breakingthe trial implants.

In certain embodiments, at least a portion of method 2100 utilizes anactuator to handle the trial implants. Step 2120 may include a step 2122of utilizing an actuator coupled with the trial implants to insert thetrial implants into uncinate joints 120. In one example of step 2122, asurgeon uses an actuator, holding a pair of trial implants, to insertthe trial implants into uncinate joints 120 from intervertebral discspace 140. One exemplary actuator is discussed below in reference toFIGS. 27 and 28. Step 2130 may include a step 2136 of utilizing anactuator to at least assist in securing the trial implants in uncinatejoints 120. In one example of steps 2122 and 2136, the actuator used instep 2122 remains coupled with the trial implants during step 2136 to atleast participate in securing the trial implants in uncinate joints 120.Step 2150 may include a step 2152 of utilizing an actuator coupled withthe trial implants to remove the trial implants. Step 2150 may combinestep 2152 with other removal methods such as tapping. In one example ofstep 2122 and 2152, the actuator used in step 2122 remains coupled withthe trial implants during step 2136 to at least participate in removingthe trial implants from uncinate joints 120.

In one embodiment, method 2100 further includes a step 2160 of insertingan IVDS implant into intervertebral disc space 140 to stabilize cervicalspine segment 180. One example of step 2160 utilizes methods and IVDSimplants known in the art.

In another embodiment, method 2100 further includes a step 2170,subsequent to step 2150, of placing implants 100 in uncinate joints 120to stabilize uncinate joints 120 permanently or for a longer period oftime, such that patient 170 leaves the procedure with implants 100 inuncinate joints 120. Method 2100 may include both of steps 2160 and2170.

FIG. 22 illustrates one exemplary method 2200 of stabilizing uncinatejoints 120 of a cervical spine segment 180 (FIG. 1) after intervertebraldiscectomy of cervical spine segment 180. Method 2200 accesses uncinatejoints 120 from intervertebral disc space 140 along medial-to-lateraldirections 220. Method 2200 may be incorporated into method 2100 (FIG.21) to implement step 2170 and, optionally, step 2160.

In a step 2210, a pair of implants 100 is inserted from intervertebraldisc space 140 into the pair of uncinate joints 120, respectively.Exemplary embodiments of implant 100, which are compatible with step2210, are discussed below in reference to FIGS. 23A-26 and 29-31.

In one embodiment, step 2210 includes a step 2212 of utilizing anactuator to insert implants 100 into uncinate joints 120 fromintervertebral disc space 140. Step 2212 is similar to step 2022 ofmethod 2000 (FIG. 20) and may be performed as discussed in reference tostep 2022.

In another embodiment, step 2210 includes a step 2214 of inserting anIVDS implant into intervertebral disc space 140 and inserting implants100 from this IVDS implant into uncinate joints 120. This IVDS implantmay be non-load bearing or partial-load bearing, as discussed inreference to FIG. 20. Examples of IVDS implants, which are compatiblewith step 2214, are discussed below in reference to FIGS. 32 and 33. Inone implementation, step 2214 includes a step 2216 of loading bone graftmaterial, with, or into, the IVDS implant to promote fusion of cervicalspine segment 180 within intervertebral disc space 140. In one exampleof step 2216, the IVDS implant has at least one void capable ofaccommodating bone graft material. Bone graft material may be loadedinto the void(s) before or after inserting the IVDS implant intointervertebral disc space 140. In another example of step 2216, the IVDSimplant is or includes a porous element substantially composed of bonegraft material.

Optionally, step 2210 includes a step 2218 of loading bone graftmaterial with, or into, implants 100 to promote fusion of uncinatejoints 120. In one example of step 2210, implants 100 have at least onevoid that carry bone graft material. Bone graft material may be loadedinto the void(s) of each implant 100 before or after inserting implant100 into uncinate joint 120. In another example of step 2210, at least aportion of each implant 100 is a porous portion substantially composedof bone graft material that promotes bone growth in the pores thereof.Since the surfaces of uncinate joints 120 are cortical bone, fusionpromoted by step 2210 may be stronger and/or faster than fusion withinintervertebral disc space 140. Method 2200 may implement step 2218together with step 2216 to achieve fusion strength and/or speed superiorto that possible when fusing only intervertebral disc space 140.

Embodiments of method 2200, which do not include step 2214, may includea step 2220 of inserting an IVDS implant into intervertebral disc space140. Step 2220 is similar to step 2050 of method 2000 and may beperformed as discussed in reference to step 2050.

Method 2200 further includes a step 2230 of securing implants 100 inuncinate joints 120. In one implementation, step 2230 includes a step2232 of securing each implant 100 in the corresponding uncinate joint120 using one or more protruding features of implant 100 to grip atleast one of superior surface 684 (FIG. 6B) and inferior surface 686,and thus securing implant 100 in uncinate joint 120. Exemplaryprotruding features include barbs, ribs, and surface texture. Exemplaryimplants compatible with step 2232 are discussed below in reference toFIGS. 23A-D, 25, and 29. Step 2230 may include a step 2234, wherein atension band is utilized to secure each implant 100 to the correspondinguncinate joint 120. In certain embodiments, step 2230 includes a step2236 of utilizing mechanical coupling with an IVDS implant inserted intointervertebral disc space 140 in step 2214 or step 2220. Step 2236 mayutilize a non-load bearing or partial-load bearing IVDS implant, asdiscussed in reference to FIG. 20. FIGS. 29-31 discussed belowillustrate one exemplary embodiment of implant 100 and one exemplaryIVDS implant, which are compatible with step 2236. In embodiments ofmethod 2200, which implement steps 2222 and 2236, step 2222 may beperformed after step 2236, without departing from the scope hereof.

Method 2000 may implement two or more of steps 2232, 2234, and 2236 incombination. Without departing from the scope hereof, method 2000 mayperform step 2230 as an integrated element of step 2210 and/or step2220.

FIGS. 23A, 23B, 23C, and 23D illustrate one exemplary tapered implant2300 for stabilizing uncinate joint 120 (FIG. 1). Tapered implant 2300is an embodiment of implant 100 (FIG. 1). Tapered implant 2300 may beimplemented in method 2000 (FIG. 20), in method 2100 (FIG. 21) as thetrial implant or the implant of step 2170, or in method 2200 (FIG. 22).FIG. 23A shows tapered implant 2300 in perspective view. FIG. 23B showstapered implant 2300 in cross-sectional side view. FIGS. 23C and 23D areelevation views of tapered implant 2300 from directions in the plane ofthe cross-sectional view of FIG. 23B. FIGS. 23A-D are best viewedtogether.

Tapered implant 2300 includes two surfaces 2322 and 2324 forming a taperwith a taper angle of 2330. Taper angle 2330 is, for example, in therange between 10° and 45°. Taper angles 2330 less than 10°, may resultin insufficient distraction of uncinate joints 120, while taper angles2330 greater than 45° may result in insufficient support of uncinatejoint 120 and/or trouble securing tapered implant 2300 in uncinate joint120. Tapered implant 2300 is configured to be placed in uncinate joint120 with surfaces 2322 and 2324 contacting superior surface 684 (FIG.6B) and inferior surface 686 of uncinate joint 120. Tapered implant 2300includes a surface 2326 generally facing intervertebral disc space 140,when tapered implant 2300 is located in uncinate joint 120.

Tapered implant 2300 has length 2340. When placed in uncinate joint 120,length 2340 is oriented along uncinate joint 120 substantially alonganterior-to-posterior direction 210. In one example, length 2340 is atleast six millimeters, for example, to provide sufficient contact area,between tapered implant 2300 and surfaces of uncinate joint 120, suchthat tapered implant 2300 is capable of supporting the load of uncinatejoint 120. Length 2340 is at most eighteen millimeters, for example, toensure that tapered implant 2300 does not encroach on the neuralforamen. In another example, length 2340 is such that tapered implant2300 protrudes from uncinate joint 120 in the anterior direction to easycoupling of tapered implant 2300 with another device, such as theactuator or extensions discussed in reference to FIGS. 21 and 22. Inthis example, length 2340 may be in the range between 15 and 70millimeters.

When implemented in method 2000, 2100, or 2200, implant 2300 is insertedinto uncinate joint 120 with the taper (characterized by taper angle2330) facing uncinate joint 120 (i.e., with surfaces 2322 and 2324facing uncinate joint 120 and surface 2326 facing away from uncinatejoint 120). Tapered implant 2300 has a maximum thickness 2346. Maximumthickness 2346 exceeds the spacing between superior surface 684 andinferior surface 686 at the locations where tapered implant 2300contacts superior surface 684 and inferior surface 686, such thattapered implant 2300 is capable of distracting uncinate joint 120. Inone embodiment, the value of maximum thickness 2346 is sufficientlylarge that maximum thickness 2346 exceeds a desired spacing betweensuperior surface 684 and inferior surface 686, at the locations wheretapered implant 2300 contacts superior surface 684 and inferior surface686, for the vast majority of patients 170. This embodiment of taperedimplant 2300 is suitable for use with the vast majority of patients 170without requiring customization or custom size selection. In oneexample, maximum thickness 2346 is in the range between four and tenmillimeters, to provide sufficient distraction of uncinate joint 120 torelieve impingement issues while fitting between cervical vertebrae 184and 186. In another example, maximum thickness 2346 is no greater thansix millimeters. In yet another example, maximum thickness 2346 isgreater than two millimeters.

In certain embodiments, tapered implant 2300 includes features 2380 thatprotrude from surfaces 2322 and 2324 and/or form fenestrations insurfaces 2322 and 2324. Each of methods 2000, 2100, and 2200 may utilizefeatures 2380 in steps 2032, 2132, and 2232, respectively, to securetapered implant 2300 in uncinate joint 120. Features 2380 may be barbs,ribs, surface texture, and/or fenestrations. For clarity ofillustration, features 2380 are not shown in FIGS. 23A and 23C.Embodiments of tapered implant 2300 that include features 2380 may beself-securing.

Although not shown in FIGS. 23A-D, tapered implant 2300 may have atleast one void capable of accommodating bone graft material, withoutdeparting from the scope hereof. Such embodiments of tapered implant2300 may be utilized in step 2024 of method 2000, in step 2170 of method2100, and in step 2218 of method 2200. Tapered implant 2300 may includea coating, for example a hydroxyapatite coating, to achieve improvedfixation of tapered implant 2300 to uncinate joint 120, withoutdeparting from the scope hereof.

In one embodiment, tapered implant 2300 is substantially composed of ametal such as titanium, titanium alloy, stainless steel, cobalt,chromium, or a combination thereof. In another embodiment, taperedimplant 2300 includes a porous portion with pores capable ofaccommodating bone graft material within uncinate joint 120, or a porousportion substantially composed of bone graft material, as discussed inreference to step 2024 of method 2000, in step 2170 of method 2100, andin step 2218 of method 2200. In one example, tapered implant 2300 issubstantially composed of, or includes, porous metal. In yet anotherembodiment, tapered implant 2300 is substantially composed of allograftbone. In a further embodiment, tapered implant 2300 is substantiallycomposed of polymer. The polymer is, for example, polyetheretherketone(PEEK) or another polyaryletherketone (PAEK) polymer. Any of the abovematerials may be used in a 3-D printing process to make tapered implant2300.

Although not shown in FIGS. 23A-D, tapered implant 2300 may further betapered along the dimension associated with length 2340 to account forthe lordosis of the cervical spine, as discussed in reference tothreaded implant 500 (FIGS. 5A and 5B), without departing from the scopehereof.

FIG. 24 illustrates another exemplary tapered implant 2400 forstabilizing uncinate joint 120. Tapered implant 2400 is similar totapered implant 2300, except that angle 2430 between surfaces 2324 and2326 is less than angle 2432 between surface 2322 and 2326.

FIG. 25 illustrates yet another exemplary tapered implant 2500 forstabilizing uncinate joint 120. Tapered implant 2500 is similar totapered implant 2400, except that the corner formed by surfaces 2322 and2324 is truncated, and the corner formed by surfaces 2324 and 2326 istruncated. Tapered implant 2500 has a minimum thickness 2510. Minimumthickness 2510 may be sufficiently small that tapered implant 2500 canenter uncinate joint 120 for the vast majority of patients 170. Minimumthickness 2510 is in the range between 0.5 and 2 millimeters, forexample.

FIG. 26 illustrates, in an anterior view, a pair of exemplary taperedimplants 2600 located in uncinate joints 120 of cervical spine segment180 (FIG. 1), after insertion into uncinate joints 120 according tomethod 2000 (FIG. 20), 2100 (FIG. 21), or 2200 (FIG. 22). Each taperedimplant 2600 is, for example, one of tapered implants 2300 (FIG. 23),2400 (FIGS. 24), and 2500 (FIG. 25). Tapered implant 2600 may be used asa trial implant.

FIG. 27 illustrates, in an axial view, one exemplary actuator 2700 forinserting tapered implants 2600 (FIG. 26) into uncinate joints 120 ofcervical spine segment 180 (FIG. 1). Actuator 2700 may be utilized bymethods 2000 (FIG. 20), 2100 (FIGS. 21), and 2200 (FIG. 22). Together,actuator 2700 and tapered implants 2600 form a system for distractinguncinate joints 120. In one example of use, tapered implants 2600 arefinal implants left in cervical spine segment 180 to stabilize cervicalspine segment 180. In another example of use, tapered implants 2600 aretrial implants, and actuator 2700 and tapered implants 2600 maycooperate to perform step 2120 of method 2100. In this example of use,tapered implants 2600, or portions of tapered implants 2600 contacting asurface of uncinate joints 120, may be made of a polymer. In a moregeneral embodiment, tapered implants 2600 is made of one or more of thematerials discussed above in reference to threaded implant 500. Any oneof these materials may be used to make tapered implant 2600 in a 3-Dprinting process.

Actuator 2700 includes a hinge 2720 and handles 2730. For the purpose ofcoupling with actuator 2700, each tapered implant 2600 includes acoupling interface 2710. A surgeon may manipulate handles 2730 tocontrol the position of tapered implants 2600 through hinge 2720, tomove tapered implants 2600 within cervical spine segment 180 alongmedial-to-lateral directions 220 (FIG. 2). In one embodiment, hinge 2720is configured for scissor action, such that tapered implants 2600 movetowards uncinate joints 120 when handles 2730 are moved away from eachother. In another embodiment, hinge 2720 is configured for reversescissor action, such that tapered implants 2600 move towards uncinatejoints 120 when handles 2730 are towards each other.

Optionally, actuator 2700 includes a dial 2760 that indicates, to thesurgeon, distance 2750 between tapered implants 2600 or another measurerelated to distance 2750. With knowledge of the shape of taperedimplants 2600, other information may be derived from distance 2750, suchas the spacing between superior surface 684 (FIG. 6B) and inferiorsurface 686. If, furthermore, a known force is applied to handles 2730,forces associated with distraction of uncinate joints 120 may be derivedfrom distance 2750. In one example of use of dial 2760, actuator 2700 isimplemented in step 2120 of method 2100 (FIG. 21) to obtain informationabout uncinate joints 120 and/or distraction of uncinate joints 120.This information may be utilized in step 2210 of method 2200 (FIG. 22),for example to select implants of suitable geometry for cervical spinesegment 180 of patient 170. In one implementation, a surgeon utilizesdial 2760 to actuate handles 2730. In this implementation, dial 2760 maybe configured to be operable in discrete increments that eachcorresponds to a known change of distance 2750. For example, eachincrement of dial 2700 corresponds to a change of distance 2750 by 0.5or 1.0 millimeters.

Although not shown in FIG. 27, tapered implants 2600 may have length2340 (FIG. 23C) sufficient to extend beyond uncinate joints 120 in ananterior direction, when tapered implants 2600 are placed in uncinatejoints 120, without departing from the scope hereof.

In addition to inserting implants 100 into uncinate joints 120, actuator2700 may serve to maintain anterior access to intervertebral disc space140, by holding aside the esophagus, muscles, and other tissue ofpatient 170.

FIG. 28 illustrates, in an axial view, exemplary extensions 2820 thatmay be coupled with tapered implants 2600 (FIG. 26) to extend taperedimplants 2600 in an anterior direction. Extensions 2820 may be used bymethods 2000 (FIG. 20), 2100 (FIGS. 21), and 2200 (FIG. 22).

Each extension 2820 has length 2850. Length 2850 is in the range between20 and 60 millimeters, for example. Each extension 2820 couples tocoupling interface 2710 of tapered implant 2600. Optionally, eachextension 2820 includes a coupling interface 2810, such that extensions2820 may be coupled with actuator 2700 (FIG. 27).

Actuator 2700 may be coupled with extensions 2820 to serve as a softtissue retractor for the surgery, with or without tapered implants 2600coupled therewith.

FIG. 29 illustrates one exemplary tapered implant 2900 for stabilizinguncinate joint 120 (FIG. 1). Tapered implant 2900 has an optional recess2910 that facilitates mechanical coupling with an IVDS implant. Taperedimplant 2900 is similar to tapered implant 2500 (FIG. 25), except foroptionally including recess 2910. Without departing from the scopehereof, tapered implant 2900 may have the shape of tapered implant 2300(FIG. 23) or tapered implant 2400 (FIG. 24), optionally modified toinclude recess 2910.

FIG. 30 illustrates one exemplary IVDS implant 3000 configured forplacement in intervertebral disc space 140 (FIG. 1) to at leastparticipate in securing tapered implants 2900 in uncinate joints 120.IVDS implant 3000 includes protruding features 3010 at opposing sidesthereof. IVDS implant 3000 may be used in steps 2050 and 2060 of method2000 (FIG. 20), and in steps 2220 and 2236 of method 2200 (FIG. 22).IVDS implant 3000 may be non-load bearing or partial-load bearing, asdiscussed in reference to FIG. 20.

IVDS implant 3000 includes a mechanism 3020 for extending distance 3080between features 3010. Optionally, each feature 3010 is shaped topreferably couple with tapered implant 2900 in recess 2910 of taperedimplant 2900 (FIG. 29). Thus, IVDS implant 3000 may couple with twotapered implants 2900.

In one embodiment, IVDS implant 3000 has at least one void capable ofaccommodating bone graft material to promote fusion in intervertebraldisc space 140. Bone graft material may be loaded into the void(s) ofIVDS implant 3000 before or after inserting IVDS implant 3000 intointervertebral disc space 140. This embodiment of IVDS implant 3000 iscompatible with step 2052 of method 2000 and with step 2222 of method2200. In another embodiment, at least a portion of IVDS implant 3000 isa porous portion substantially composed of bone graft material thatpromotes fusion in intervertebral disc space 140. This embodiment ofIVDS implant 3000 is compatible with step 2052 of method 2000 and withstep 2222 of method 2200.

FIG. 31 illustrates exemplary use of IVDS implant 3000 (FIG. 30) in step2060 of method 2000 (FIG. 20) or in step 2236 of method 2200 (FIG. 22).FIG. 31 shows, in an anterior view, IVDS implant 3000 located inintervertebral disc space 140 of cervical spine segment 180 (FIG. 1). Apair of tapered implants 2900 (FIG. 29) are located in uncinate joints120 of cervical spine segment 180.

Referring now to FIGS. 20 and 29-31 in combination, method 2000 insertstapered implants 2900 into uncinate joints 120 in step 2020. In step2050, method 2000 inserts IVDS implant 3000 into intervertebral discspace 140 (FIG. 1) In step 2060, a surgeon actuates mechanism 3020 toextend distance 3080 along medial-to-lateral directions 220 (FIG. 2)such that features 3010 apply pressure on tapered implants 2900. Byvirtue of this pressure, IVDS implant 3000 at least participates insecuring tapered implants 2900 in uncinate joints 120.

Referring now to FIGS. 22 and 29-31 in combination, method 2200 insertstapered implants 2900 into uncinate joints 120 in step 2210. In step2220, method 2200 inserts IVDS implant 3000 into intervertebral discspace 140 (FIG. 1) In step 2236, a surgeon actuates mechanism 3020 toextend distance 3080 along medial-to-lateral directions 220 such thatfeatures 3010 apply pressure on tapered implants 2900. By virtue of thispressure, IVDS implant 3000 at least participates in securing taperedimplants 2900 in uncinate joints 120.

Without departing from the scope hereof, features 3010 and recesses 2910may be switched, such that tapered implants 2900 have features 3010 andIVDS implant 3000 optionally has recesses 2910.

FIG. 32 illustrates one exemplary implant-loading system 3200 forstabilizing uncinate joints 120 of cervical spine segment 180 (FIG. 1)from intervertebral disc space 140. Implant-loading system 3200 may beutilized in step 2214 of method 2200 (FIG. 22).

Implant-loading system 3200 includes a cage 3210 with a rotationmechanism 3215. Implant-loading system 3200 further includes a pair oftapered implants 2600 (FIG. 26) and a pair of connectors 3220. Eachconnector 3220 connects a respective tapered implant 2600 to rotationmechanism 3215. Connectors 3220 are wound around rotation mechanism in aspiral pattern. Connectors 3220 may be sheets, for example made ofmetal, plastic, or a combination thereof. Upon clockwise rotation ofrotation mechanism 3215 (as indicated by arrow 3230), tapered implants2600 move away from cage 3210. Without departing from the scope hereof,rotation mechanism 3215 may be configured to move tapered implants 2600away from cage 3210 upon counter-clockwise rotation of rotationmechanism 3215.

In one embodiment, cage 3210 has at least one void capable ofaccommodating bone graft material to promote fusion in intervertebraldisc space 140. Bone graft material may be loaded into the void(s) ofcage 3210 before or after inserting cage 3210 into intervertebral discspace 140. This embodiment of cage 3210 is compatible with step 2052 ofmethod 2000 and with step 2222 of method 2200. In another embodiment, atleast a portion of cage 3210 is a porous portion substantially composedof bone graft material that promotes fusion in intervertebral disc space140. This embodiment of cage 3210 is compatible with step 2052 of method2000 and with step 2222 of method 2200. Cage 3210 may be non-loadbearing or partial-load bearing, as discussed in reference to FIG. 20.

Without departing from the scope hereof, spiral-wound connectors 3220may be replaced by linear connectors having teeth that couple with agear of rotation mechanism 3215.

FIG. 33 shows implant-loading system 3200 (FIG. 32) as implemented instep 2214 of method 2200 (FIG. 22). Implant-loading system 3200 isinserted into intervertebral disc space 140. A surgeon rotates rotationmechanism 3215 to move tapered implants 2600 into uncinate joints 120 ofcervical spine segment 180. The surgeon may utilize a tool, such as aphillips-head screwdriver/drill, a star-head screwdriver/drill, or ahexagonal wrench, to actuate rotation mechanism 3215.

Combinations of Features

Features described above as well as those claimed below may be combinedin various ways without departing from the scope hereof. For example, itwill be appreciated that aspects of one uncinate joint stabilizer, orassociated system or method, described herein may incorporate or swapfeatures of another uncinate joint stabilizer, or associated system ormethod, described herein. The following examples illustrate possible,non-limiting combinations of embodiments described above. It should beclear that many other changes and modifications may be made to themethods and device herein without departing from the spirit and scope ofthis invention:

(A1) A method for stabilizing a cervical spine segment may includeimplanting a respective uncinate joint stabilizer into each uncinatejoint of the cervical spine segment to stabilize the uncinate joints andthereby stabilize the cervical spine segment.

(A2) In the method denoted as (A1), in the step of implanting, eachuncinate joint stabilizer may be configured to preserve motion of therespective uncinate joint.

(A3) In the method denoted as (A1), in the step of implanting, eachuncinate joint stabilizer may be configured to promote fusion of therespective uncinate joint. For example, each uncinate joint stabilizermay include bone graft material, or be configured to accept bone graftmaterial, to promote fusion of the respective uncinate joint.Alternatively, in the step of implanting, each uncinate joint stabilizermay be composed of a non-fusing material.

(A4) In the method denoted as (A1), in the step of implanting, eachuncinate joint stabilizer may be a temporary uncinate joint stabilizercomposed of a biodegradable material, for temporary stabilization of therespective uncinate joint.

(A5) In any of the methods denoted as (A1) through (A4), in the step ofimplanting, the uncinate joint stabilizers may be configured tocooperate to bear at least a portion of load of the cervical spinesegment to maintain spacing between cervical vertebrae of the cervicalspine segment.

(A6) In any of the methods denoted as (A1) through (A5), the step ofimplanting may include inserting each uncinate joint stabilizer along ananterior-to-posterior direction.

(A7) In the method denoted as (A6), the step of inserting may includeinserting each uncinate joint stabilizer into the respective uncinatejoint while leaving intervertebral disc of the cervical spine segmentundisturbed.

(A8) In either or both of the methods denoted as (A6) and (A7), the stepof inserting may include inserting each uncinate joint stabilizerpercutaneously.

(A9) In any of the methods denoted as (A6) through (A8), each uncinatejoint stabilizer may be cannulated, and the step of inserting mayinclude inserting each uncinate joint stabilizer over a guide wire.

(A10) The method denoted as (A9) may further include inserting the guidewire through longus colli muscle.

(A11) Either of both of the methods denoted as (A9) and (A10) mayfurther include inserting the guide wire under imaging guidance.

(Al2) In the method denoted as (A8), the step of inserting may includeinserting each uncinate joint stabilizer through a respective cannula.

(A13) Any of the methods denoted as (A6) through (A12) may furtherinclude, during the step of inserting each uncinate joint stabilizer,monitoring, using imaging guidance, locations of (a) each uncinate jointstabilizer and (b) instrumentation used to insert each uncinate jointstabilizer.

(A14) In the method denoted as (A13), the step of monitoring may includemonitoring the locations relative to vertebral artery on side of spineassociated with the uncinate joint stabilizer, to prevent damaging thevertebral artery.

(A15) Any of the methods denoted as (A6) through (A14) may furtherinclude distracting each uncinate joint.

(A16) In the method denoted as (A15), the step of distracting mayinclude distracting each uncinate joint using a distraction tool, andremoving the distraction tool from the uncinate joint prior to the stepof implanting.

(A17) In the method denoted as (A15), the step of distracting mayinclude distracting each uncinate joint using the respective uncinatejoint stabilizer during the step of inserting.

(A18) In any of the methods denoted as (A6) through (A17), each uncinatejoint stabilizer may have threads, and the step of inserting may includethreading each uncinate joint stabilizer into the respective uncinatejoint using the threads.

(A19) The method denoted as (A18) may further include (a) in the step ofthreading, threading each uncinate joint stabilizer into the respectiveuncinate joint such that the threads contact uncinate joint surfacesonly of a selected one of superior and inferior vertebral bodies of thecervical spine segment, and (b) securing each uncinate joint stabilizerto only the selected one of superior and inferior vertebral bodies topreserve motion of the cervical spine segment.

(A20) In the method denoted as (A19), the step of securing may includeutilizing tension band formed by at least one ligament of the cervicalspine segment.

(A21) In either or both of the methods denoted as (A19) and (A20), thestep of securing may include, for each uncinate joint stabilizer,affixing mounting hardware to the uncinate joint stabilizer and thevertebral body.

(A22) In the method denoted as (A18), in the step of inserting, and foreach uncinate joint, the threads may contact both superior and inferiorsurfaces of the uncinate joint.

(A23) The method denoted as (Al) may further include (a) in the step ofimplanting, inserting each uncinate joint stabilizer into the respectiveuncinate joint along a medial-to-lateral direction starting fromintervertebral disc space of the cervical spine segment, and (b)securing each uncinate joint stabilizer to the respective uncinatejoint.

(A24) In the method denoted as (A23), in the step of inserting eachuncinate joint stabilizer, each uncinate joint stabilizer may include atapered implant element for interfacing with superior and inferioruncinate joint surfaces, and the step of inserting each uncinate jointstabilizer may include, for each uncinate joint, distracting theuncinate joint by inserting the uncinate joint stabilizer into theuncinate joint along the medial-to-lateral direction with thinnerportion of the tapered implant element facing the uncinate joint.

(A25) In the method denoted as (A24), the step of securing may includesecuring each uncinate joint stabilizer to the respective uncinate jointusing features protruding from the tapered implant element.

(A26) In either or both of the methods denoted as (A24) and (A25), thestep of securing may include securing each uncinate joint stabilizer tothe respective uncinate joint by, in part, utilizing tension band formedby at least one ligament associated with the respective uncinate joint.

(A27) Any of the methods denoted as (A24) through (A26) may furtherinclude, before the step of distracting, opening anterior portion of theintervertebral disc space to open access path for the uncinate jointstabilizers.

(A28) Any of the methods denoted as (A24) through (A27) may furtherinclude (a) in the step of distracting, temporarily securing eachuncinate joint stabilizer to the respective uncinate joint usingfeatures protruding from the tapered implant element, (b) after the stepof distracting, performing cervical discectomy to remove at least aportion of intervertebral disc, (c) after the step of performingcervical discectomy, further distracting each uncinate joint by moving,along the medial-to-lateral direction, each uncinate joint stabilizerfurther into the respective uncinate joint, and (d) after the step offurther distracting, securing each uncinate joint stabilizer to therespective uncinate joint using the features protruding from the taperedimplant element.

(A29) In the method denoted as (A28), each of the steps of distracting,performing cervical discectomy, and further distracting may includemoving each uncinate joint stabilizer using an actuator mechanicallycoupled with the uncinate joint stabilizers.

(A30) The method denoted as (A23) may further include, before the stepof inserting each uncinate joint stabilizer, (a) opening anteriorportion of the intervertebral disc space to open access path for taperedtrial implants and (b) distracting the uncinate joints by inserting eachtapered trial implant into a respective uncinate joint along themedial-to-lateral direction.

(A33) In the method denoted as (A30), the step of distracting mayinclude using an actuator to insert each tapered trial implant into therespective uncinate joint to distract the respective uncinate joint,wherein the actuator accesses the tapered trial implants from anteriorside of the cervical spine segment.

(A32) In the method denoted as (A31), the step of distracting mayinclude using the actuator to distract both uncinate jointssimultaneously.

(A33) Any of the methods denoted as (A30) through (A32) may furtherinclude temporarily securing each tapered trial implant to therespective uncinate joint using features protruding from the taperedtrial implant.

(A34) Any of the methods denoted as (A30) through (A33) may furtherinclude, after the step of distracting and before the step of insertingeach uncinate joint stabilizer, performing cervical discectomy to removeat least a portion of intervertebral disc of the cervical spine segment.

(A35) In the method denoted as (A34), the step of performing cervicaldiscectomy may include mechanically coupling discectomy instrumentationto the tapered trial implants, and using the discectomy instrumentationto remove the at least a portion of intervertebral disc.

(A36) In the method denoted as (A35), the discectomy instrumentation mayinclude a soft tissue retractor.

(A37) Any of the methods denoted as (A34) through (A36) may furtherinclude removing each tapered trial implant after the step of performingcervical discectomy, and the step of inserting each uncinate jointstabilizer further comprising distracting each uncinate joint by moving,along a medial-to-lateral direction, each uncinate joint stabilizer intothe respective uncinate joint.

(A38) In any of the methods denoted as (A30) through (A37), the step ofinserting each uncinate joint stabilizer may include moving the uncinatejoint stabilizer using an actuator mechanically coupled with theuncinate joint stabilizers.

(A39) Any of the methods denoted as (A23) through (A38) may furtherinclude, after the step of inserting each uncinate joint stabilizer,depositing bone graft material in the intervertebral disc space topromote fusion of the cervical spine segment.

(A40) Any of the methods denoted as (A23) through (A39) may furtherinclude, after the step of inserting each uncinate joint stabilizer,placing an intervertebral-disc-space (IVDS) implant in theintervertebral disc space.

(A41) In the method denoted as (A40), the step of placing an IVDSimplant may include mechanically coupling the IVDS implant with theuncinate joint stabilizers.

(A42) In the method denoted as (A41), the step of mechanically couplingmay include adjusting lateral dimension of the IVDS implant to matchdistance between the uncinate joint stabilizers.

(A43) In any of the methods denoted as (A40) through (A42), the step ofsecuring each uncinate joint stabilizer comprising utilizing mechanicalcoupling with the IVDS implant.

(B1) A system for stabilizing a cervical spine segment may include apair of uncinate joint stabilizers for stabilizing a respective pair ofuncinate joints of the cervical spine segment, wherein each uncinatejoint stabilizer is elongated along a lengthwise dimension andconfigured for placement in the respective uncinate joint with thelengthwise dimension substantially oriented along ananterior-to-posterior direction of the cervical spine segment, andwherein each uncinate joint stabilizer has height in a heightwisedimension orthogonal to the lengthwise dimension and the height isconfigured to define spacing of the respective uncinate joint.

(B2) In the system denoted as (B1), the height may be in the range fromtwo millimeters to seven millimeters, and/or the length may be in therange from six to eighteen millimeters.

(B3) In either or both of the systems denoted as (B1) and (B2), eachuncinate joint stabilizer may have length in the lengthwise dimensionand width in a widthwise dimension orthogonal to the lengthwise andheightwise dimensions, wherein the width is less than the length andgreater than the height.

(B4) In the system denoted as (B3), the width and height may becompatible with percutaneous insertion of each uncinate joint stabilizerinto the respective uncinate joint along an anterior-to-posteriordirection.

(B5) In either or both of the systems denoted as (B3) and (B4), each ofthe width and the height may be no greater than 10 millimeters.

(B6) In any of the systems denoted as (B1) through (B5), each uncinatejoint stabilizer may include a textured surface for securing theuncinate joint stabilizer to the respective uncinate joint.

(B7) In any of the systems denoted as (B1) through (B6), each uncinatejoint stabilizer may be configured for insertion into the respectiveuncinate joint along an anterior to posterior direction; and the systemmay further include, for each uncinate joint stabilizer, a locking levercoupled to trailing or leading end of the uncinate joint stabilizer,wherein the interface between the uncinate joint stabilizer and thelocking lever is configured to allow rotation of the locking lever aboutan axis in the lengthwise dimension, wherein extent of the locking leverin a first dimension transverse to the lengthwise dimension is less thanthe height to allow insertion of the uncinate joint stabilizer withoutthe locking lever contacting surfaces of the respective uncinate joint,and wherein extent of the locking lever in a second dimension orthogonalto the first dimension and the lengthwise dimension is greater than theheight to lock the locking lever to at least one surface of the uncinatejoint by rotating the locking lever about the axis so as to secure theuncinate joint stabilizer in the respective uncinate joint.

(B8) In the system denoted as (B7), the locking lever may include ajagged surface for locking the locking lever to the at least onesurface.

(B9) In either of both of the systems denoted as (B7) and (B8), when thelocking lever is oriented to align the second dimension with theheightwise dimension, the locking lever may extend beyond the uncinatejoint stabilizer in both directions away from the axis along theheightwise dimension to enable locking of the locking lever to bothsuperior and inferior surfaces of the respective uncinate joint.

(B10) In either of both of the systems denoted as (B7) and (B8), whenthe locking lever is oriented to align the second dimension with theheightwise dimension, the locking lever may extend beyond the uncinatejoint stabilizer only in one direction away from the axis along theheightwise dimension, to enable locking of the locking lever to only oneof superior and inferior surfaces of the respective uncinate joint.

(B11) Any of the systems denoted as (B1) through (B6) may furtherinclude, for each uncinate joint stabilizer, a screw coupled to theuncinate joint stabilizer for threading the uncinate joint stabilizerinto the respective uncinate joint along the anterior-to-posteriordirection by contacting threads of the screw to at least one surface ofthe respective uncinate joint.

(B12) In the system denoted as (B11), each uncinate joint stabilizer mayhave two openings that allow the threads to contact the superior andinferior surfaces, respectively, for inserting the uncinate jointstabilizer into the respective uncinate joint by threading the screwinto the respective uncinate joint, wherein the interface between theuncinate joint stabilizer and the screw allows for rotation of theuncinate joint stabilizer about axis of screw to rotate the uncinatejoint stabilizer around the screw to secure the uncinate jointstabilizer to superior and inferior surfaces of the uncinate joint anddefine the spacing after inserting the uncinate joint stabilizer intothe respective uncinate joint.

(B13) In the system denoted as (B14), each uncinate joint stabilizerhaving jagged exterior surfaces for securing the uncinate jointstabilizer to the superior and inferior surfaces.

(B14) In any of the systems denoted as (B1) through (B6), each uncinatejoint stabilizer may include a generally cylindrical portion withcylinder axis in the lengthwise dimension, wherein the generallycylindrical portion has threads for threading the uncinate jointstabilizer into the respective uncinate joint along theanterior-to-posterior direction.

(B15) In the system denoted as (B14), the generally cylindrical portionmay include a porous portion for accommodating bone graft material andbone growth.

(B16) In either or both of the systems denoted as (B14) and (B15), thethreads may be interrupted by one or more fenestrations, oriented alongthe lengthwise direction, wherein the fenestrations are configured toaccommodate one or more materials selected from the group consisting ofbone graft material, bone growth, and tissue displaced from therespective uncinate joint by the uncinate joint stabilizer.

(B17) In any of the systems denoted as (B14) through (B16), eachuncinate joint stabilizer may be cannulated along the cylinder axis forinsertion into the respective uncinate joint over a respective guidewire.

(B18) The system denoted as (B17) may further include an interface forcoupling the uncinate joint stabilizer to a drill for drilling theuncinate joint stabilizer into the respective uncinate joint over therespective guide wire.

(B19) In the system denoted as (B18), the interface may be located on anend face of the uncinate joint stabilizer, the end face generally facingalong the lengthwise direction.

(B20) In any of the systems denoted as (B14) through (B19), eachuncinate joint stabilizer may include a tapered portion that (a) isadjacent to the generally cylindrical portion, (b) is offset from thegenerally cylindrical portion in a direction along the lengthwisedimension, and (c) has decreasing extent transverse to the cylinder axiswith increasing distance along the cylinder axis away from the generallycylindrical portion, such that the tapered portion eases insertion ofthe uncinate joint stabilizer into the respective uncinate joint alongthe anterior-to-posterior direction.

(B21) In any of the systems denoted as (B14) through (B20), thegenerally cylindrical portion may have diameter to implement the height.

(B22) In any of the systems denoted as (B14) through (B21), eachuncinate joint stabilizer may be configured to expose the threads atleast in two opposite-facing directions in the heightwise dimension, tosecure the uncinate joint stabilizer to both superior and inferiorsurfaces of the respective uncinate joint using the threads.

(B23) In any of the systems denoted as (B14) through (B20), eachuncinate joint stabilizer may further include comprising a housing forpartly containing the generally cylindrical portion, wherein the housingincludes (a) an opening from which the threads protrude in a firstdirection along the heightwise dimension, to allow the threads tocontact a selected one of superior and inferior surfaces of therespective uncinate joint, and (b) a material portion shielding thethreads from contacting a non-selected one of the superior and inferiorsurfaces.

(B24) In the system denoted as (B23), the material portion may include asmooth surface for contacting the non-selected one of the superior andinferior surfaces while allowing relative movement between the uncinatejoint stabilizer and the non-selected one of the superior and inferiorsurfaces, to form a motion-preserving uncinate joint stabilizer.

(B25) The system denoted as (B24) may further include mounting hardwarefor affixing each uncinate joint stabilizer to vertebra associated withthe selected one of the superior and inferior surfaces.

(B26) In the system denoted as (B25), the mounting hardware may includea bracket for interconnecting the uncinate joint stabilizers externallyto intervertebral disc space of the cervical spine segment.

(B27) In the system denoted as (B26), the bracket may include a portionconfigured to contact anterior facing surface of vertebral bodyassociated with the selected one of the superior and inferior surfaces.

(B28) In the system denoted as (B27), the portion may include anaperture for accepting a screw at location where the portion contactsthe anterior facing surface, to secure the uncinate joint stabilizers tothe vertebral body using the bracket and the screw.

(B29) In the system denoted as (B28), the aperture may include alaterally oriented slot to accommodate a range of distances between theuncinate joints.

(B30) Either or both of the systems denoted as (B28) and (B29) mayfurther include the screw.

(B31) In any of the systems denoted as (B1) through (B6), each uncinatejoint stabilizer may include a tapered portion for interfacing withsuperior and inferior surfaces of the respective uncinate joint, whereinthe tapered portion has a gradient in height along the widthwisedimension, to enable insertion of the uncinate joint stabilizer into therespective uncinate joint from intervertebral disc space of the cervicalspine segment.

(B32) In the system denoted as (B31), the tapered portion may have (a) afirst surface for contacting the superior surface of the respectiveuncinate joint and (b) a second surface for contacting the inferiorsurface of the respective uncinate joint, wherein each of the first andsecond surfaces has at least one protruding feature for securing theuncinate joint stabilizer to the respective uncinate joint.

(B33) In either or both of the systems denoted as (B31) and (B32), thetapered portion may have taper angle in range between 10° and 45°.

(B34) Any of the systems denoted as (B31) through (B33) may furtherinclude a cage configured for placement in the intervertebral disc spaceand for inserting, from the intervertebral disc space, the uncinatejoint stabilizers into the respective uncinate joints.

(B35) The system denoted as (B34) may further include a pair ofconnecting elements for connecting the pair of uncinate jointstabilizers, respectively, to the cage, and an actuator, connected toeach of the connecting elements, for extending the connecting elementsto insert the uncinate joint stabilizers into the uncinate joints,respectively.

(B36) In any of the systems denoted as (B1) through (B35), each uncinatejoint stabilizer may be composed of metal.

(B37) In the system denoted as (B36), the metal may be selected from thegroup consisting of titanium, titanium alloy, stainless steel, cobalt,chromium, and a combination thereof.

(B38) In any of the systems denoted as (B1) through (B35), each uncinatejoint stabilizer may include a polymer.

(B39) In the system denoted as (B38), the polymer being selected fromthe group consisting of (a) polyetheretherketone (PEEK) and (b) otherpolyaryletherketone (PAEK) material.

(B40) Any of the systems denoted as (B1) through (B35) may be composedof biodegradable material or a non-fusing material.

(B41) In the system denoted as (B40), the biodegradable material may beselected from the group consisting of lactulose, proline, polyglycolicacid, a derivative of polyglycolic acid, poly-L-lactic acid, aderivative of poly-L-lactic acid, and a combination thereof.

(C1) A system for distracting uncinate joints of a cervical spinesegment may include two tapered elements and an actuator configured tocouple with the tapered elements and change distance between the taperedelements, to insert the tapered elements into the uncinate joints,respectively, from intervertebral disc space of the cervical spinesegment.

(C2) In the system denoted as (C1), each of the tapered elements may beelongated in a lengthwise dimension and having height in a heightwisedimension orthogonal to the lengthwise dimension, wherein the height hasa gradient in a widthwise dimension orthogonal to the lengthwise andheightwise dimensions to define tapering of the tapered element.

(C3) Either or both of the systems denoted as (C1) and (C2) may furtherinclude two extensions for extending the tapered elements, respectively,along the lengthwise dimension, wherein each extension has lengthsufficient to protrude in anterior direction from the respectiveuncinate joint, the actuator being coupled to the tapered elements viathe extensions.

(C4) In the system denoted as (C3), each extension may include aninterface for holding instrumentation for protecting soft tissue.

(C5) In either or both of the systems denoted as (C3) and (C4), eachextension may be integrally formed with the respective tapered element.

(C6) In either or both of the systems denoted as (C3) and (C4), eachextension may be removably coupled with the respective tapered element.

(C7) In any of the systems denoted as (C1) through (C6), each taperedelement may include polymer.

(C8) In any of the systems denoted as (C1) through (C6), each taperedelement may include at least one portion for contacting surfaces of therespective uncinate joint, wherein the portion is composed of polymer.

(C9) In any of the systems denoted as (C1) through (C8), the taperedelements may taper away from each other when coupled with the actuator,such that the height of each implant decreases in direction away fromthe other implant.

(C10) In any of the systems denoted as (C1) through (C9), each taperedelement may taper from height less than one millimeter to height nogreater than six millimeters.

(C11) In any of the systems denoted as (C1) through (C9), each taperedelement may taper from height less than two millimeters to heightgreater than two millimeters.

(C12) In any of the systems denoted as (C1) through (C11), each taperedelement may include features protruding from the tapered element fortemporarily securing the tapered elements to the uncinate joints.

(C13) In any of the systems denoted as (C1) through (C12) furtherincluding a coupling mechanism for coupling and uncoupling the actuatorwith the tapered elements.

(C14) In any of the systems denoted as (C1) through (C13), the actuatormay include (a) two connecting members for mechanically coupling withthe tapered elements, respectively, (b) two handles for actuating theactuator, and (c) a hinge, coupled with the connecting members and thehandles, for translating action of the handles to the connectingmembers.

(C15) In the system denoted as (C14), the hinge may be configured forreverse scissor action.

(C16) In the system denoted as (C14), the hinge may be configured forscissor action.

(C17) Any of the systems denoted as (C1) through (C16) may furtherinclude an indicator for indicating separation between the taperedelements when coupled with the actuator.

Changes may be made in the above devices, systems, and methods withoutdeparting from the scope hereof. It should thus be noted that the mattercontained in the above description and shown in the accompanyingdrawings should be interpreted as illustrative and not in a limitingsense. The following claims are intended to cover generic and specificfeatures described herein, as well as all statements of the scope of thepresent devices, systems, and methods, which, as a matter of language,might be said to fall therebetween.

What is claimed is:
 1. A system for stabilizing a cervical spinesegment, comprising: a pair of uncinate joint stabilizers forstabilizing a respective pair of uncinate joints of the cervical spinesegment, each uncinate joint stabilizer being elongated along alengthwise dimension and configured for placement in the respectiveuncinate joint with the lengthwise dimension substantially orientedalong an anterior-to-posterior direction of the cervical spine segment,each uncinate joint stabilizer having height in a heightwise dimensionorthogonal to the lengthwise dimension, the height being configured todefine spacing of the respective uncinate joint, each uncinate jointstabilizer including a generally cylindrical portion with cylinder axisin the lengthwise dimension, the generally cylindrical portion havingthreads for threading the uncinate joint stabilizer into the respectiveuncinate joint along the anterior-to-posterior direction, the threadsbeing interrupted by one or more fenestrations, oriented along thelengthwise direction, the fenestrations being configured to accommodateone or more materials selected from the group consisting of bone graftmaterial, bone growth, and tissue displaced from the respective uncinatejoint by the uncinate joint stabilizer.
 2. The system of claim 1, theheight being in range from two millimeters to seven millimeters.
 3. Thesystem of claim 1, length of each uncinate joint stabilizer in thelengthwise dimension being in range from six to eighteen millimeters. 4.The system of claim 1, extent of each uncinate joint stabilizer indimensions orthogonal to the lengthwise dimension being compatible withpercutaneous insertion of each uncinate joint stabilizer into therespective uncinate joint along the anterior-to-posterior direction. 5.The system of claim 1, extent of each uncinate joint stabilizer indimensions orthogonal to the lengthwise dimension being no greater than10 millimeters.
 6. The system of claim 1, the generally cylindricalportion having diameter to implement the height.
 7. The system of claim6, the generally cylindrical portion being tapered along the lengthwisedimension to accommodate lordosis of the cervical spine segment
 8. Thesystem of claim 1, each uncinate joint stabilizer being configured toexpose the threads at least in two opposite-facing directions in theheightwise dimension, to secure the uncinate joint stabilizer to bothsuperior and inferior surfaces of the respective uncinate joint usingthe threads.
 9. The system of claim 8, the generally cylindrical portioncomprising a porous portion for accommodating bone graft material andbone growth.
 10. The system of claim 1, each uncinate joint stabilizerbeing cannulated along the cylinder axis for insertion into therespective uncinate joint over a respective guide wire.
 11. The systemof claim 10, further comprising an interface for coupling the uncinatejoint stabilizer to a driver for drilling the uncinate joint stabilizerinto the respective uncinate joint over the respective guide wire. 12.The system of claim 11, the interface being located on an end face ofthe uncinate joint stabilizer, the end face generally facing along thelengthwise direction.
 13. The system of claim 1, each uncinate jointstabilizer comprising a tapered portion that (a) is adjacent to thegenerally cylindrical portion, (b) is offset from the generallycylindrical portion in a direction along the lengthwise dimension, and(c) has decreasing extent transverse to the cylinder axis withincreasing distance along the cylinder axis away from the generallycylindrical portion, such that the tapered portion eases insertion ofthe uncinate joint stabilizer into the respective uncinate joint alongthe anterior-to-posterior direction.
 14. The system of claim 1, eachuncinate joint stabilizer further comprising a housing for partlycontaining the generally cylindrical portion, the housing including: anopening from which the threads protrude in a first direction along theheightwise dimension, to allow the threads to contact a selected one ofsuperior and inferior surfaces of the respective uncinate joint; and amaterial portion shielding the threads from contacting a non-selectedone of the superior and inferior surfaces.
 15. The system of claim 14,the material portion comprising a smooth surface for contacting thenon-selected one of the superior and inferior surfaces while allowingrelative movement between the uncinate joint stabilizer and thenon-selected one of the superior and inferior surfaces, to form amotion-preserving uncinate joint stabilizer.
 16. The system of claim 14,further comprising mounting hardware for affixing each uncinate jointstabilizer to vertebra associated with the selected one of the superiorand inferior surfaces.
 17. The system of claim 1, each uncinate jointstabilizer being composed of metal.
 18. The system of claim 17, themetal being selected from the group consisting of titanium, titaniumalloy, stainless steel, cobalt, chromium, and a combination thereof. 19.The system of claim 1, each uncinate joint stabilizer including apolymer.
 20. The system of claim 19, the polymer being selected from thegroup consisting of (a) polyetheretherketone (PEEK) and (b) otherpolyaryletherketone (PAEK) material.
 21. The system of claim 1 beingcomposed of biodegradable material.
 22. The system of claim 21, thebiodegradable material being selected from the group consisting oflactulose, proline, polyglycolic acid, a derivative of polyglycolicacid, poly-L-lactic acid, a derivative of poly-L-lactic acid, and acombination thereof.
 23. A system for stabilizing a cervical spinesegment, comprising: a pair of uncinate joint stabilizers forstabilizing a respective pair of uncinate joints of the cervical spinesegment, each uncinate joint stabilizer being elongated along alengthwise dimension and configured for placement in the respectiveuncinate joint with the lengthwise dimension substantially orientedalong an anterior-to-posterior direction of the cervical spine segment,each uncinate joint stabilizer having height in a heightwise dimensionorthogonal to the lengthwise dimension, the height being configured todefine spacing of the respective uncinate joint; and for each uncinatejoint stabilizer, a screw coupled to the uncinate joint stabilizer forthreading the uncinate joint stabilizer into the respective uncinatejoint along the anterior-to-posterior direction by contacting threads ofthe screw to at least one surface of the respective uncinate joint. 24.The system of claim 23, each uncinate joint stabilizer having twoopenings that allow the threads to contact the superior and inferiorsurfaces, respectively, for inserting the uncinate joint stabilizer intothe respective uncinate joint by threading the screw into the respectiveuncinate joint, interface between the uncinate joint stabilizer and thescrew allowing for rotation of the uncinate joint stabilizer about axisof the screw to rotate the uncinate joint stabilizer around the screw tosecure the uncinate joint stabilizer to superior and inferior surfacesof the uncinate joint and define the spacing after inserting theuncinate joint stabilizer into the respective uncinate joint.
 25. Thesystem of claim 24, each uncinate joint stabilizer having jaggedexterior surfaces for securing the uncinate joint stabilizer to thesuperior and inferior surfaces.
 26. The system of claim 23, the uncinatejoint stabilizers being composed of a non-fusing material.
 27. A systemfor stabilizing a cervical spine segment, comprising: a pair of uncinatejoint stabilizers for stabilizing a respective pair of uncinate jointsof the cervical spine segment, each uncinate joint stabilizer beingelongated along a lengthwise dimension and configured for placement inthe respective uncinate joint with the lengthwise dimensionsubstantially oriented along an anterior-to-posterior direction of thecervical spine segment, each uncinate joint stabilizer having height ina heightwise dimension orthogonal to the lengthwise dimension, theheight being configured to define spacing of the respective uncinatejoint, each uncinate joint stabilizer being configured for insertioninto the respective uncinate joint along an anterior to posteriordirection; and for each uncinate joint stabilizer, a locking levercoupled to trailing or leading end of the uncinate joint stabilizer,interface between the uncinate joint stabilizer and the locking leverbeing configured to allow rotation of the locking lever about an axis inthe lengthwise dimension, extent of the locking lever in a firstdimension transverse to the lengthwise dimension being less than theheight to allow insertion of the uncinate joint stabilizer without thelocking lever contacting surfaces of the respective uncinate joint,extent of the locking lever in a second dimension orthogonal to thefirst dimension and the lengthwise dimension being greater than theheight to lock the locking lever to at least one surface of the uncinatejoint by rotating the locking lever about the axis so as to secure theuncinate joint stabilizer in the respective uncinate joint.
 28. Thesystem of claim 27, the locking lever including a jagged surface forlocking the locking lever to the at least one surface.
 29. The system ofclaim 27, when the locking lever is oriented to align the seconddimension with the heightwise dimension, the locking lever extendingbeyond the uncinate joint stabilizer in both directions away from theaxis along the heightwise dimension, to enable locking of the lockinglever to both superior and inferior surfaces of the respective uncinatejoint.
 30. The system of claim 27, when the locking lever is oriented toalign the second dimension with the heightwise dimension, the lockinglever extending beyond the uncinate joint stabilizer only in onedirection away from the axis along the heightwise dimension, to enablelocking of the locking lever to only one of superior and inferiorsurfaces of the respective uncinate joint.
 31. The system of claim 27,each uncinate joint stabilizer having length in the lengthwise dimensionand width in a widthwise dimension orthogonal to the lengthwise andheightwise dimensions, the width being less than the length and greaterthan the height.
 32. The system of claim 27, each uncinate jointstabilizer comprising a textured surface for securing the uncinate jointstabilizer to the respective uncinate joint.